Untitled - Laboratoire d'Astrophysique de l'Observatoire de Grenoble

LABORATOIRE D’ASTROPHYSIQUE
DE GRENOBLE
UMR 5571
Scientific Report 2002-2010
Activities: 2002-2005
Research Plans: 2006-2010
December 2005
3

Contents
I Foreword 13
1 15
II Executive Summary 17
1.1 Presentation of LAOG . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
1.1.1 A young, fast growing laboratory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
1.1.2 Evolutions: scientific strategy and team synergy . . . . . . . . . . . . . . . . . . . . . . . 20
1.1.3 A brief overview of the scientific teams of LAOG . . . . . . . . . . . . . . . . . . . . . . . 24
1.1.4 Studentship at LAOG . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
1.1.5 Selected highlights and comparison with objectives of the previous report . . . . . . . . . 25
1.2 Bibliography . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
1.3 Relations with the outside world . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
1.3.1 Relations with and within the Observatory of Grenoble (OSUG) . . . . . . . . . . . . . . 28
1.3.2 Relations with IRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
1.3.3 Relations with the University and with other local laboratories . . . . . . . . . . . . . . . 29
1.3.4 The European dimension of LAOG . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
1.3.5 Publicizing LAOG’s research: outreach and patents . . . . . . . . . . . . . . . . . . . . . 30
1.4 Budget: resources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
1.5 From dreams to reality: Human resources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
1.6 The 2007-2010 prospective and beyond . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
1.6.1 Main scientific objectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
1.6.2 Long-term strategic questions for LAOG . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
1.7 Conclusions: A vision for the post-2010 future of LAOG . . . . . . . . . . . . . . . . . . . . . . . 38
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III Team ASTROMOL 41
2 Presentation and Scientific Objectives 43
2.1 Presentation of Astromol: composition, goals and summary of activities . . . . . . . . . . . . . . 43
2.2 Observations at the telescopes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
2.3 Development of astrophysical models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
2.4 Molecular physics: theories and codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
2.5 Publications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
2.6 Teaching and students formation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
2.7 National and international collaborations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
3 Results 49
3.1 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
3.2 Star Formation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
3.2.1 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
3.2.2 The deuteration in the first phases of star formation . . . . . . . . . . . . . . . . . . . . . 50
3.2.3 The hot corinos of solar type protostars . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
3.2.4 The outflows of protostars . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
3.2.5 The intermediate/high mass protostars . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
3.2.6 The X-rays from young protostars . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
3.2.7 Dust around protostars . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
3.3 Molecular Physics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
3.3.1 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
3.3.2 Potential energy surfaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
3.3.3 Energy transfer processes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
3.4 High Performance Computing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
3.5 Proto-planetary Disks: where Astromol meets FOST . . . . . . . . . . . . . . . . . . . . . . . . . 62
4 Perspectives 65
4.1 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
4.2 Scientific goals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
4.2.1 Star Formation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
4.2.2 Molecular Physics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68
4.3 The involvement in the large international projects: Herschel and ALMA . . . . . . . . . . . . . 69
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4.4 The European Network “The Molecular Universe” . . . . . . . . . . . . . . . . . . . . . . . . . . 70
4.5 Cosmology: a new frontier for Astromol ? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
4.6 The needs of Astromol : accretion and recruitment . . . . . . . . . . . . . . . . . . . . . . . . . . 72
5 Selected Publications 74
IV Team FOST 77
6 Introduction of the team & Science Results 79
6.1 FOST: a short presentation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
6.2 Scientific Highlights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
6.3 Selected topics in Star Formation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80
6.3.1 Young Accretion Disks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81
6.3.2 The star-disk interaction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85
6.3.3 Physics of Jets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87
6.3.4 Observations of Debris disks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87
6.3.5 Dynamical Models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88
6.3.6 Other topics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88
6.4 Selected topics on the IMF and the properties of low-mass populations . . . . . . . . . . . . . . . 90
6.4.1 Nearby Star Forming Regions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90
6.4.2 Selected Intermediate Age Clusters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92
6.4.3 The Solar Neighbourhood . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93
6.5 Selected topics on Extra-Solar Planets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96
6.5.1 Exoplanets around M Dwarfs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97
6.5.2 Exoplanets around F- and A-stars . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98
6.5.3 Exoplanets in Nearby associations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99
7 Future Research Directions 101
7.1 Research Plans . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101
7.2 Needs in personnel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102
8 Appendices 104
8.1 Staff . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104
8.1.1 permanent staff . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104
8.1.2 Post-docs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104
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8.1.3 Graduate Students . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105
8.2 Awards and Prizes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105
V Team GRIL 107
9 Presentation of the team 109
9.1 Foundation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109
9.2 A specific expertise . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109
9.3 Organization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110
9.4 Related activities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110
10 Scientific rationale 111
10.1 Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111
10.1.1 Key astrophysical questions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111
10.1.2 Related instrumental evolution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111
10.1.3 Current trend of large equipments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112
10.1.4 Increasing networking process . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112
10.2 Strategy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112
10.2.1 Well defined priorities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112
10.2.2 Focusing on three complementary axii . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113
10.2.3 The principles of our involvement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114
10.2.4 A logical sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114
11 Results 116
11.1 Towards high dynamic with Adaptive Optics (AO) . . . . . . . . . . . . . . . . . . . . . . . . . . 116
11.1.1 The first generation: NAOS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116
11.1.2 The high contrast imaging: VLTPF . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116
11.1.3 Instrumental Research and development activities . . . . . . . . . . . . . . . . . . . . . . 118
11.2 Bringing optical interferometry into mainstream astronomy . . . . . . . . . . . . . . . . . . . . . 120
11.2.1 The classical approach: AMBER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120
11.2.2 The innovative integrated optics: IONIC on the IOTA and VLTI interferometers . . . . . 122
11.2.3 Combining up to eight telescopes of the VLTI array: VITRUV . . . . . . . . . . . . . . . 122
11.2.4 Instrumental Research and development activities . . . . . . . . . . . . . . . . . . . . . . 123
11.2.5 JMMC and European Interferometry Initiative . . . . . . . . . . . . . . . . . . . . . . . . 125
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11.3 Cameras and detectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126
11.3.1 Towards wide-field cameras: WIRCam . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126
11.3.2 Research and development activities in photon counting superconducting detectors . . . 126
12 Perspectives 129
12.1 Adaptive optics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129
12.1.1 Instruments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129
12.1.2 R&D activities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131
12.1.3 Means and methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131
12.2 Optical interferometry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 132
12.2.1 Instruments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 132
12.2.2 Software development for interferometry . . . . . . . . . . . . . . . . . . . . . . . . . . . 133
12.2.3 R&D activities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133
12.2.4 Means and methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 134
12.3 Cameras and detectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 134
12.3.1 Instrument support technology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135
12.3.2 R&D activities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135
12.3.3 Means and methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135
13 Recruitment plan 137
14 Appendix 139
14.1 Staff . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139
14.1.1 Permanent staff . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139
14.1.2 PhD students . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139
14.1.3 Other contributors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139
14.2 Main publications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139
14.3 Industrial development . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141
14.3.1 Patents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141
14.3.2 Technological transfer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141
14.4 Highlights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141
14.5 Awards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 142
14.6 Acronyms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 142
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VI Team SHERPA 145
15 Results 147
15.1 History and group composition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147
15.2 Specific approach . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147
15.3 Accretion-Ejection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 148
15.3.1 The self-similar model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 148
15.3.2 Application to different astrophysical contexts . . . . . . . . . . . . . . . . . . . . . . . . . 148
15.4 Transport phenomena in accretion-ejection flows . . . . . . . . . . . . . . . . . . . . . . . . . . . 150
15.4.1 Jet stability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150
15.4.2 Transport in accretion disks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150
15.5 Physics of high energy sources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 151
15.5.1 Seyfert galaxies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 151
15.5.2 Blazars and the “two-flow” model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 152
15.5.3 Microquasars . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153
15.6 Relativistic Plasmas and Cosmic Rays . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 154
15.6.1 Relativistic plasmas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 154
15.6.2 Cosmic Rays . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 154
15.7 Heavy numerical simulations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 156
15.8 Astrocladistics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157
15.9 Participation in large collaborations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157
15.10 Doctoral formation and Schools . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 158
15.11 Scientific Highlights (2002-2005) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 158
16 Perspectives 160
VII APPENDICES 163
17 Appendix 1: General organization of LAOG 165
17.1 Management structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 165
17.2 Management tools and quality control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 166
18 Appendix 2: LAOG Technical group & facilities 167
18.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 167
18.2 Teams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 167
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18.3 Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 168
19 Appendix 3: Staff Responsabilities 169
19.1 International . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 169
19.1.1 Astromol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 169
19.1.2 FOST . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 169
19.1.3 GRIL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 170
19.1.4 SHERPA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 170
19.2 Workshops . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 171
19.2.1 FOST . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 171
19.3 National . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 171
19.3.1 Astromol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 171
19.3.2 FOST . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 172
19.3.3 GRIL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 173
19.3.4 SHERPA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 174
20 Appendix 4: The Jean Marie Mariotti Center 176
20.1 Mission . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 176
20.2 Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 176
20.3 Statut . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 177
20.4 Budget . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 177
20.5 Direction et personnel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 177
20.6 Le centre de réalisation logicielle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 177
20.7 Production informatique . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 178
20.8 Organisation de services informatiques distribués . . . . . . . . . . . . . . . . . . . . . . . . . . . 178
20.9 Groupes de Recherche et Développement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 179
20.10 Formation des utilisateurs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180
20.11 Conduite de projets européens . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180
20.12 L’Euro-Interferometry Initiative . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180
20.13 Darwin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 182
20.14 Relations avec l’ESO et le MSC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 182
20.15 Prospective . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 183
11

Part I
Foreword: Presentation of the Report
The welcome web page of the LAOG as of October 6, 2005
13

Chapter 1
The last Visiting Committee (known as “Evaluation Committee” in France) of LAOG took place on Jan. 22,
2002, i.e., a little less than four years ago. It examined the activity of LAOG covering the previous period
1999-2001, and its prospective for the period 2003-2006. In the present report, written in preparation for next
Evaluation Committe, set to meet in Grenoble on Nov. 3-4, 2005, LAOG scientific activities are described
for the period 2002-2005, covered by the previous prospective exercise, and the present prospective covers the
period 2007-2010 (and even beyond, as will be seen). The ”Activity” parts of the report have thus taken place
under two Directors: C. Perrier until Dec. 31, 2002, and T. Montmerle since Jan. 1st, 2003.
The present document (in English) constitutes the scientific part of the report; the administrative part (in
French), with lists of personnel, detailed budgetary data, etc., is given in a separate document. The complete
bibliography covering the period 2001-2005 is also given as a separate document.
Overall, nearly a decade of scientific activity and projects (prospective) is described.
More precidely, this report tries to summarize in 120 pages not only four years of LAOG actvities (i.e.,
about 400 refereed papers, totalling about 5000 printed pages), but also four to ten years of projects ahead of
us. The presentation is straightforward. As will be explained, the activities of LAOG are now conducted by
four scientific teams. Thus each team describes its activities and projects in a specific “part” of the present
Report. These four contributions are preceded by an “Executive Summary”, which gives a broad view of LAOG,
explains its structure, and summarizes the activities and projects of the teams in a synthetic fashion.
Several appendices give more details (see part VII):
- Appendix in chapter 17 gives some information about LAOG’s management structure;
- Appendix in chapter 18 describes the structure and activities of the Technical group;
- Appendix in chapter 19 lists the national and international science management and responsibilites of LAOG
members;
- Appendix in chapter 20 explains in detail the goals and activities of the “Centre Jean-Marie Mariotti” for
interferometry.
Finally, to help the reader identify what are precisely the scientific contributions of LAOG to a given topic
(as opposed to the work being conducted elsewhere on the same topic), we have resorted to a little typographic
trick when giving references in the text:
- LAOG references (i.e., comprizing at least one LAOG author) relevant to the current activity period (2002-
2005) are given in italics (Laog et al. 2004), and can be found in the list of “selected references” at the end of
each part, and/or in the general bibliography;
- LAOG references to older work are given also in italics, but in full (Laog et al. 2000, A&A, 360, 123);
- Non-LAOG references are given in roman, also in full (Nonlaog et al., 2000, A&A, 360, 234).
The Executive Summary part of this report has been prepared by Thierry Montmerle (Director) and Jean-
Louis Monin (Deputy-Director). The team parts have been prepared by the team leaders: Cecilia Ceccarelli,
François Ménard, Guy Pelletier, Christian Perrier and Pierre Kern (for the Technical group).
Grenoble, April 18, 2006
15

Part II
Executive Summary
A 18th century view of the formation of the solar system
17

1.1 Presentation of LAOG
1.1.1 A young, fast growing laboratory
When one takes into account the relatively young age of LAOG as it presently is, i.e., housed in the new
buildings which were completed in 1991 under the Directorship of C. Bertout, the increase in manpower has
been spectacular, from nearly 40 researchers, engineers, administrative staff and students, to nearly 100 now.
Figure 1.1 shows the evolution of LAOG since 1999, broken down in several categories: (i) permanent staff
(researchers: CNRS, professors and assistant professors [enseignants-chercheurs], astronomers, engineers, technicians
and administrative staff [ITA/IATOS]; (ii) non-permanent staff (contracts, including post-docs; PhD
students [doctorants]). As can be seen from this figure, this fast demographic evolution is due to a combination
of several factors: the hiring of young researchers (8), the return and “accretion” of other researchers from other
institutes (3), the hiring of new engineers (2) (compensating for retirements), an increase in the PhD student
population (9), and, most notably, the arrival of collaborators under contract (administration, post-docs, etc.;
7).
Figure 1.1: Demographic evolution in LAOG since 1999. The large increase starting in 2000 is due primarily to
the appearance of personnel under contracts (including post-docs), and also to a strong increase of the number
of PhD students, itself following the increase in the number of researchers (new positions and accretion from
other institutes).
Even though a few staff members will retire during the 2006-2010 period, it is likely that, after some stability
in the last two years (arrivals compensating for departures) there will likely be again a net demographic increase
over the same period, provided LAOG succeeds in hiring the number of new young researchers (∼ 7 − 9 ?) and
technicians and engineers (∼ 3 − 5) it needs to fulfill its scientific ambitions, as argued in the last section. This
increase does not take into account the possibility that researchers and post-docs from other institutes might
join us, as was the case during the previous period. It is thus likely that the 100-mark will be crossed soon, and
that LAOG will have increased by at least another ∼ 10% in 2010.
In itself, such a strong expansion testifies both to the quality and attractiveness of the work being conducted
at LAOG, and to the continued, unfailing support of national and international research agencies and science
committees, as well as of Université Joseph-Fourier (UJF) of Grenoble. The research community as a whole has
supported LAOG by selecting its members for awards: the “Société Française d’Astronomie et d’Astrophysique”
Compaq Prize to one of its young researchers (F. Malbet, 2003), two prizes from the Académie des Sciences to
more senior researchers (J. Bouvier, 2002, and A.-M. Lagrange, 2005), the “Cristal du CNRS” (the highest award
19

of CNRS for technicians and engineers) to LAOG’s Technical Director P. Kern (2004; the second such award
after E. Le Coarer in 1999), and the “Palmes Académiques” (a Ministry of Education award for professional
excellence) to LAOG’s Head of Administration F. Bouillet (2004). In addition, LAOG has had until recently
the highest concentration of “Institut Universitaire de France” professors (G. Pelletier as senior member, J.-L.
Monin and G. Henri as junior members).
We thereore believe that LAOG is poised for a bright future and exciting science. As the present report aims
at showing, there is no “growth crisis” at LAOG, because of continuous and sometimes radical adaptation to a
constantly changing and challenging environment. We are convinced that this “Spirit of LAOG”, felt across all
personnel categories, has been one of the strongest assets of this laboratory since its creation.
1.1.2 Evolutions: scientific strategy and team synergy
Major evolutions have taken place at LAOG since 2002, with the aim of better fulfilling its major scientific goals
and of making them more prominent and visible to the community and funding agencies, while accommodating
an ever-growing population. In short, LAOG switched from a research structure of nine small thematic teams
(sometimes as small as three individuals), supported by a technical group, and a theoretical team, to a simpler,
more visible structure of four large teams. This evolution took place in two steps.
• Following the recommendation of the previous Evaluation Committee in 2002 to look for a way to regroup
the existing small scientific teams, and strongly encouraged by the new Director, the LAOG researchers,
after many constructive internal discussions, decided to create two new “topical” teams, named “Astromol”
and “FOST”, while keeping the theoretical group (Sherpas) intact. (See details below.)
• After some time, it was however realized that instrumental research activities, central to the building of
new instruments for large telescopes in relation to the scientific goals of LAOG, were not adequately taken
into account. Technological developments are traditionnally strong at LAOG, and were conducted both
by researchers and high-level engineers on a project-by-project basis. It was thus decided in mid-2004 to
create a new, transverse group, the “GRIL”, where researchers and engineers would exchange ideas and
work together globally, both as an official recognition of instrumental developments as a genuine research
activity, and as a strategic and advisory group to the Director while keeping the scientific goals of LAOG
in mind. In this team, most of the researchers also belong to one of the topical teams –in practice today
the FOST team. Last but not least, the existence of such a team provides a correct, visible framework for
PhD students working on instrumental topics.
Figure 1.2 and Figure 1.3 display for comparison the previous organigram (2002) and the new organigram
(2005), which will be discussed in more detail below.
As a result, LAOG today is structured in four roughly balanced research teams (totalling 44 permanent
staff), three topical and one instrumental, and in a technical group which is responsible for conducting the
building of instruments after approval by GRIL (and of course after having been selected by external agencies).
Figure 1.4 displays their respective sizes.
To understand these evolutions, and before proceeding to describe the teams in more detail in the next
section, it is appropriate to start with the main scientific axes developed over the years since the creation of
LAOG a little more than a decade ago. These can be summarized as follows:
• Origins: the physics of low-mass star formation and early evolution, and the path to planet
formation;
• High energies and astrophysical plasmas: the accretion-ejection phenomenon and its implications
for astroparticle physics;
• Instrumental research: high angular resolution and high dynamic range instruments for
large telescopes.
As schematically illustrated by Figure 1.5, these three scientific axes are strongly interrelated: the study
of the conditions for star and planet formation (disks and jets from young stars and protostars; exoplanets), a
20

Figure 1.2: Old LAOG organigram (2002). The scientific activities were divided in nine teams, while a separate
“Project group” included all the engineers and technicians.
21

Figure 1.3: New LAOG organigram (2005). Due to internal reorganization, the number of LAOG teams has been
reduced to four (in short: Molecular astrophysics, Star and planet formation, High-energies and astrophysical
plasmas, Instrumental research). The last one, named GRIL, is a transverse group comprizing both researchers
and engineers. The former “Project group” has become a “Technical group”, and its tasks have been subdivided
into two software groups (one working for the common service of LAOG, the other for instrumental projects),
and in three hardware groups (mechanics, general instrumentation, electronics). The last box lists projects
delivered during the current activity period (AMBER, WIRCAM), as well as projects under development. See
text for details.
22

Figure 1.4: The current repartition of the four LAOG scientific teams. Note that the GRIL team includes both
researchers (some being also part of the FOST team) and engineers involved in instrumental research activities,
he total being 4+5=9. The corresponding number counts the main contributors to GRIL not already counted
in the other teams.
major federating force at LAOG, requires both high angular resolution and high dynamic range, i.e., contrast,
on the one hand (an instrumental and observational issue) and a study of the accretion-ejection phenomenon
(a theoretical MHD topic, with applications in particular to young stars), on the other.
Figure 1.5: The contributions of the four LAOG scientific teams to their federating topic: observations and
theory of the accretion-ejection phenomenon, as keys to the physics of star formation and early evolution (left),
and as a starting point towards exoplanet formation (right).
In the new structure in four teams, it should be stressed that while each team provides original contributions
to the field of star and planet formation, the teams also have their own specific scientific field of research (e.g.,
fundamental astrochemistry for Astromol, brown dwarfs and exoplanets for FOST, relativistic plasmas for
Sherpas, general research in adaptive optics and interferometry for GRIL). This approach is certainly one of
the main specificities of LAOG when compared to other major international laboratories involved in this field.
In other words, LAOG as a whole is more than the mere sum of its teams.
In contrast, comparing with the previous report the careful reader will notice that one field of study has
disappeared from LAOG: the structure and evolution of post-main sequence stars. The main reason is the
untimely death of Manuel Forestini in spring 2003 (a young Assistant Professor, he was not even 40), from a
23

heart attack. Manuel went back to this topic after his well-known work on pre-main sequence (PMS) stellar
evolution. This challenge was all the more formidable that, contrary to PMS stars which draw their energy
only from gravitation, the late stages of stellar evolution involve a highly complex network of nuclear reactions.
His main legacy is the Starevol code, which is publicly available on the web and is now widely used by the
stellar evolution community worldwide. In addition to his time-consuming high-level responsibilities at UJF,
Manuel was a whole scientific team in himself, although he was on his way to build a real one with a PhD
student (see Siess and Leclair 2005); when he passed away, however, there was no one to continue this activity
at LAOG. (Fortunately, the field is continuing, chiefly under Manuel’s former PhD student Lionel Siess, now a
Professor in Marcel Arnould’s group in Brussels.) The proceedings of an international scientific colloquium held
at LAOG in 2004 “Stars and Nuclei: a Tribute to Manuel Forestini” is in preparation (EDP Sciences, edited by
T. Montmerle and C. Kahane).
Ancient Astronomy
One must also mention the work of C. Nozières on History of ancient Astronomy (Michel-Nozières 2002). She
is studying in the original Assyrian language, old astronomical texts on the measurement of the variation of
lunar visibility through the year.
1.1.3 A brief overview of the scientific teams of LAOG
We here give a brief “identity card” of each team. The following parts of this report (III to VI) will be devoted
to a much more detailed, individual account of their recent activities and prospective.
• The first axis (Origins: low-mass star formation and early evolution, and the path to planet formation),
is shared by all four teams. In alphabetical order:
(i) the “Astromol” (= molecular astrophysics) team mainly studies the physico-chemistry of the
earliest stages of star formation (molecular clouds, prestellar cores, protostars, and also young disks and
molecular outflows; timescale ∼ 10 5 − 10 6 yrs), but also includes fundamental astrochemistry (reaction
rates, transition probabilities, etc.).
Permanent staff: 10. PhDs completed: 2; underway: 2. Team leader: C. Ceccarelli (Astronomer).
(ii) the “FOST” (= star and planet formation, brown dwarfs) team focuses on later stages of
star formation, mainly the physics of star-disk interactions, evolved disks and the conditions for planet
formation (structural features like gaps and rings, dust grain evolution in disks, etc.; timescale ∼ 10 6 −10 7
yrs), and also on the formation mechanisms of binaries and the “Initial Mas Function” (IMF). A specific
activity within the team is the study of brown dwarfs, both as astronomical objects by themselves, and as
intermediate bodies between low-mass stars and exoplanets. The search and characterization of exoplanets
are themselves an increasing part of the FOST activities. The team contributes a lot to observations made
with LAOG-built instruments and to their interpretation.
Permanent staff: 13 + 7 shared with GRIL. PhDs completed: 5 + 1 with GRIL; underway:
9 + 3 with GRIL + 1 with Sherpas. Team leader: F. Ménard (CNRS).
(iii) the “GRIL” (= instrumental research group at LAOG) team concentrates on strategic issues
in research & development (R&D) for future instruments and detectors. While the situation may evolve, so
far GRIL’s responsibility has been to contribute to the development of optical and near-IR instruments for
large ground-based telescopes (ESO, CFH) with the highest spatial resolution (for instance with the goal
to resolve the inner parts of protoplanetary disks, i.e., within 1 AU at 450 pc, say), by way of adaptive
optics and interferometry, and/or the highest dynamic range (adaptive optics to image exoplanets as
closely as possible from their host star).
Permanent staff: 9 (including 8 engineers) + 7 shared with FOST. 1 PhDs completed: 3 +
1 with FOST; underway: 8 + 3 with FOST. Team leader: C. Perrier (Astronomer).
(iv) the “Sherpas” (= “sources of high energies and relativistic physics in accretion-ejection
structures”, in full) team is essentially involved in MHD theory calculations, with particular emphasis on
the accretion-ejection phenomenon in astrophysics. Here it mainly applies models to star-disk interactions
and disk-driven jets, where magnetic fields, instead of gravitation, play a dominant role.
1 two engineers qualified to supervised PhDs (’HDR’ in french)
24

Permanent staff: 7. PhDs completed: 2; underway: 2 + 1 with FOST. Team leader: G.
Pelletier (UJF Professor).
• The second axis (High energies and astrophysical plasmas: the accretion-ejection phenomenon and its
implications for astroparticle physics) is specific to Sherpas team. The team studies the accretion-ejection
phenomenon, here in the context of compact X-ray binaries and AGNs (“two-fluid jets”), where gravitation
(in addition to magnetic fields) plays a dominant role, and also fundamental research on accretion disk
transport and jet stability, as well as cosmic-ray acceleration to ultra-high energies (UHE) by relativistic
shock waves. The Sherpas team is actively involved in the HESS European collaboration, which operates
an array of ˘ Cerenkov telescopes in Namibia with the capability to detect very high-energy γ-rays (≥ 10 12
eV).
• The third axis (Instrumental research in the field of high angular resolution and high dynamic range
for large telescopes), is specific to GRIL. Because of the current wavelength range, there are significant
interactions with the FOST (young stars) and Sherpas (AGNs) teams, but nothing in principle prevents
GRIL to get LAOG involved in mm and/or high-energy instrumentation at the initiative of Astromol or
Sherpas (there are currently no such projects however.) Note that once an instrument reaches the actual
building stage, it leaves GRIL and becomes a “project” of the technical group, headed by P. Kern. GRIL is
also in charge of helping decide strategic orientations of LAOG for the long-term future, like contributing
to ELTs (extremely large telescopes), interferometric developments in Antarctica at Dome C, or future
space missions (e.g., Darwin, ESA, > 2015). (These questions will be expanded below.)
1.1.4 Studentship at LAOG
Students have always been a large component of LAOG personnel. On average, there are about 20 PhD being
prepared in our lab (6 new students hired every year). The majority of these students get a research grant from
the French Ministry of research, while other are paid by specific grants based on instrumental projects. Since
the year 2001 (TBC), the LAOG also welcomes an increasing number of young researchers on post-doctoral
positions. These positions are awarded by the ministry of research, or the CNRS on the basis of a scientific
project. They are also provided by the European networks we are more and more involved into. LAOG has
defined a number of procedures to associate its PhD students to the lab every day life:
• two students are elected members of the LAOG advisory board
• every year, we organize a “thesis workshop” during a full day where the PhD students can present their
work before the rest of the lab.
Table 1.1: Number of PhD students from 2003 to 2005 in LAOG
Year 2003 2004 2005
22 16 18
1.1.5 Selected highlights and comparison with objectives of the previous report
Given the large differences between the old and the new structures of LAOG, it is difficult to compare the
prospective of the old teams, as presented in the previous prospective report, and the resulting “activity”
part of the present report, without going into unnecessary details. The most important changes were due to
movements of researchers leaving or joining LAOG, namely an increase in mm astronomy activities, and the
arrival of a new expertise: X-rays, taken mainly as tracers of magnetic fields in young stars. Most of the other
results have been obtained acording to plans, sometimes even faster (like the first image of an exoplanetary
mass object.)
Consequently, we prefer to summarize the main results obtained by the teams over the 2002-2005 period, as
follows.
25

Figure 1.6: PhD student repartition in 2005. A: ASTROMOL; F: FOST; G: GRIL; S: SHERPAS
• Astromol
• FOST
• GRIL
– Discovery of doubly and triply deuterated molecules in low mass star forming regions, from the prestellar
core to the proto-planetary phases. These studies have greatly contributed to the developement
of a new class of models for the molecular deuteration.
– Discovery and imaging of the hot corinos, warm and dense regions at the center of solar type protostars.
These regions, whose sizes are comparable to those of the Solar System, are highly enriched
of complex organic molecules.
– High-accuracy multidimensional calculations of molecule-molecule and electron-molecule interactions,
based upon advanced treatments of electronic correlation.
– State-of-the-art calculations of molecule-molecule and electron-molecule inelastic collisional rates.
These results, whose accuracy rivals available experiments, are of great importance for modelling of
the interstellar gas from cold regions to harsh environments.
– Direct images of planetary mass companions around 2 objects in young nearby associations: 2MASSW J1207334-
393254 (5 MJup at 55 AU) and AB Pic (13-14 MJup at 250AU) (Chauvin et al. 2004, 2005). These
results were obtained with the NACO adaptive optics instrument, built in part at LAOG.
– Dynamical masses: First astrometric mass determination for a planet, around Gliese 876b: 1.89
±0.34MJup (Benedict et al. 2002). Similarly, astrometric meaurements of stellar masses in binary systems.
Accuracies on the mass of a few percents are reached on nearby L dwarf 2MASSW J0746425+2000321
(Bouy et al. 2004) and ∼ 10% for young stars V773 Tau, DF Tau, and TWA 5 (Duchêne et al. 2003).
– The Universality of the “present day” Mass Function observed down to at least 30 MJup (the sensitivity
limit of the surveys carried) in several young open clusters (e.g., Moraux et al. 2005).
– The very inner structure of young Herbig Be star MWC 297 revealed by NIR interferometry. For
the first time, the respective contributions from the disk and the wind are separated spatially and
spectrally within the inner 1AU of the central source. These results were obtained at the VLTI with
the interferometric recombiner AMBER, built in part at LAOG (Malbet et al. 2005).
– The NAOS (Nasmyth Adaptive Optics System) instrument for the VLT and the AMBER instrument
for the VLTI, partially or fully integrated at LAOG, are now offered to the ESO astronomical
community after successful commissioning and science verification phases (resp. early 2002 and early
2004).
– The VLT-PF (“Planet Finder”) proposal for a second generation VLT instrument led by LAOG was
selected by the ESO STC in April 2005 after a successfull 2-year phase A study, awaiting formal
decision by the next ESO Council.
– Magnetic or electrostatic deformable micro-mirrors have reached full functionality. Magnetic ones
are now made available through industrial production and an LETI-LAOG electrostatic prototype is
currently under test.
26

– First fringes in the H band with the IOTA 3 telescopes interferometer by means of an integrated
optics beam combiner (Monnier et al. 2004, Kraus et al. 2005) and first formal demonstration of
single mode guiding at 10 microns in the IODA project (Labadie et al. 2005).
– Creation and development of the Centre Jean-Marie Mariotti (JMMC) with partners (Nice, and
ASHRA). Consecutive creation of the European interferometry Initiative (EII) coupling interferometry
networks of the OPTICON EC I3, and high-level involvement (PI, PSci) in three of its four
JRAs. The goal of JMMC is to develop user-friendly software, and more generally preparation and
advice, for the use and promotion of the VLTI. (See Appendix in chapter 20
• Sherpa
– Transport of cosmic rays in chaotic magnetic fields. The knowledge of the diffusion coefficients of
cosmic rays is crucial for astrophysical applications and especially for astroparticle physics, both
for mastering the cosmic ray propagation and the efficiency of Fermi acceleration. They have been
computed with a Monte Carlo simulation as a function of the cosmic ray rigidity and the spectrum
of the magnetic field (characterized by its index and its degree of irregularities). It is found that
the transverse diffusion coefficient follows a law which is nor Bohm nor quasi-linear, but a law that
stems from the analysis of the spatial chaos of field lines. This result is important to estimate the
confinement time of cosmic-rays in galaxies and in extragalactic jets (Casse et al. 2002).
– Stationary accretion disks launching super-fast-magnetosonic waves. This is the last paper in the
series on Magnetized Accretion-Ejection Structures (MAES), which represents the only available
self-consistent model of a self-confined jet driven by an accretion disk (with the disk fully resolved),
able to cross all three MHD critical points. Biases induced by the self-similarity contraints are
discussed (Ferreira & Casse 2004).
– On the relevance of subcritical turbulence to accretion disk transport. This paper solves a riddle
dating back to the seventies, and which has given rise to an important controversy in the last ten
years. Namely, it is shown that a linearly stable, keplerian hydrodynamic flow is indeed turbulent
through non linear mechanisms, but that this turbulence has a low efficiency in terms of angular
momentum transport, with a Shakura-Sunyaev parameter α < 10 −5 . The discrepancy between
numerical simulations and laboratory experiments is explained away (Lesur & Longaretti 2005).
– The bulk Lorentz factor crisis of TeV Blazars: evidence for an inhomogeneous pile-up energy distribution.
It is shown that the theoretical Lorentz factors of Blazar jets are contradicted by the
source statistics which implies Lorentz factors of order 3, whereas homogeneous models require 50 or
more. The only way out of this conundrum is to take the jet stratification into account, so that high
energy photons are not produced in the same region as low energy ones. Observations then require
mono-energetic distribution functions whereas most models make use of power-law distributions. In
contradistinction with the dominant view, this work shows that (1) jets do not need to be highly
relativistic, and (2) turbulence rather than shocks is at the origin of the production of high energy
particles (Henri & Saugé 2005).
1.2 Bibliography
A major innovation is the creation of an automated bibliography.
Visit http://www-laog.obs.ujf-grenoble.fr/Laog/publications.php. The principle is that, once a list of
names (LAOG personnel, evolving if necessary) is provided, an automated request is sent to ADS every week.
Thus, new publications (including ArXiv preprints) are regularly added to the bibliographical database. It is
recognized that ADS does not cover all publications (for instance it does not access chemistry journals or some
conferences), so that manual corrections and updates are still necessary, which is done under the responsibility of
the LAOG authors. While this innovation (partly outsourced to a private software company) was implemented
for the present Evaluation exercise, it is a long-term investment and an extremely useful tool that can be
improved in the future (new names, new databases consulted, etc.).
The major quantitative results emerging from the 2001-2005 report bibliography, available in a separate
printed document are as follows: 2
2 The bibliography to be used for the present report (covering the period 2001-2005) is however not exactly identical to the web
bibliography. In particular, care has been taken to weed out refereed papers of LAOG members before their arrival or after their
27

• LAOG researchers (and publishing engineers) have published about 400 refereed papers, and about as
many contributions to conferences. This means an average of 80 refereed papers and 80 conference papers per
year, or about 2 + 2 papers per year per researcher/publishing engineer. This result is all the more remarkable
since many researchers have teaching duties (up to 50% of their time), as is the case for several engineers, and/or
important responsibilities in national and international science or advisory committees. (These responsibilities
are listed in Appendix in chapter19.)
• There is a significant, and increasing, number of invited papers in international conferences, on the order
of 10 per year on average. A notable exception will be in 2005: at the Protostars and Planets V conference
(held every 5-7 yrs since its creation), which is expected to gather 700 participants in Hawaii in late October,
a pre-selection of papers has resulted in 9 invited talks for LAOG, the highest number of the whole community
in the field of Star and Planet formation (the next laboratory is NASA Ames, Calif., with 8 papers). More
generally, LAOG considers that part of its scientific policy should be to communicate and exchange results with
the international community in conferences, and devotes a significant part of its budget to support this activity.
• The bibliography also lists several patents, relevant to micro- and nanotechnologies, testifying of the will
of LAOG to transfer knowledge to the industry while protecting the intellectual property of its engineers.
1.3 Relations with the outside world
1.3.1 Relations with and within the Observatory of Grenoble (OSUG)
Following a ministerial reform in 1999, the original Grenoble Observatory was expanded, including the “Laboratoire
d’Astrophysique de Grenoble” (LAOG) and three Earth sciences laboratories (glaciology, hydrology, and
geophysics), as well as a newly created planetology laboratory (the “Laboratoire de Planétologie de Grenoble”,
LPG). The new structure, gathering nearly 500 people, became the “Observatoire des Sciences de l’Univers de
Grenoble” (OSUG). This reform created a new administrative layer to which the new LAOG had to adapt, but
also brought new resources and new contacts with other fields. Within OSUG, while each laboratory has its own
goals and priorities, new scientific collaborations between LAOG and other OSUG laboratories are emerging,
in glaciology for projects in Antarctica (see GRIL part), and with LPG (dust grain evolution in the young solar
system and young stellar disks, meteorite irradiation, exoplanetary atmospheres, etc.). It is planned to develop
these collaborations in the coming years. It is also worth mentioning that discussions take place from time to
time with the geophysicists on topics such as turbulence and dynamo. The state of the art, or the physical
parameter space (e.g., Reynolds numbers for turbulence), was just too different in the relevant areas for these
collaborations to take place immediately, but the situation is improving.
1.3.2 Relations with IRAM
The roots of LAOG can be found in the GAG (Groupe d’Astrophysique de Grenoble), a group created by
Alain Omont as a scientific support for the newly created Institut de Radioastronomie Millimétrique, IRAM
(1979). Thus most of the founding fathers of LAOG had strong ties with IRAM (the others were the embryo
of the Sherpas group around G. Pelletier), and were in particular heavily involved in mm astronomy. The
new emphasis on high-angular resolution in astronomy in 1991, with a fast hiring of young researchers and
engineers developing science and optical-IR instruments around this topic, resulted in a decline of the mm
involvement of the newly created LAOG. IRAM, which is by construction a service institute, pursued on its
side the instrumental developments for the Pico Veleta 30m single-dish radiotelescope and the Plateau de Bure
Interferometer thereafter. LAOG researchers involved in mm astronomy either joined IRAM to participate in
its development, or continued to use IRAM facilities by way of observing proposals (sometimes including IRAM
co-Is), but the scientific collaborations between the two institutes remained limited, in spite of a few attempts
on both sides (PhD theses, schools...). It is however fair to add that there were on many occasions informal
exchanges between the instrumental teams of LAOG and IRAM. Again, IRAM is a service institute, subject
to the constraints of its funding agencies in Germany and Spain in addition to CNRS in France, and it is not
departure (case of new researchers, post-docs, etc.), references to CDS (Strasbourg) databases (case of tables published only in
electronic form), etc. The difference between the two is about 10% of the total number of publications.
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clearly in its goals to have scientific activities of its own (although it does have PhD students and post-docs).
This is a constant obstacle to a full-fledged collaboration.
LAOG strongly hopes that this situation will evolve, by promoting together as much as possible activities
around the topic of star formation: common science meetings, formal co-supervision of PhD students, etc. A
common project around a data analysis center for interferometry, CEXIA, is also under way (see next section).
1.3.3 Relations with the University and with other local laboratories
LAOG is, in the French system, and like most research laboratories, a so-called “Mixed Research Unit” (UMR),
which means that its operations are funded both by CNRS and the Ministry of Education, via the UJF. In
practice, the University contributes to the operating budget and provides the buildings, as well as Professors
and student support, while CNRS provides the scientific equipment and permanent researcher positions. (More
funding and soft money for positions are increasingly provided by contracts, see below.)
This also means that LAOG has a responsibility in graduate studies, the teaching being provided by professors
via the “Formation and Research Unit” (UFR) in Physics. LAOG is also heavily involved in the UJF
administration and management of teaching: one of its members (Prof. C. Kahane) is leading the reform team
for undergraduate studies at UJF Presidency level, another (Prof. G. Henri) is responsible for the graduate
studies in astrophysics at the Physics UFR (which, among others, provides many of the LAOG PhD students).
UJF is an active partner also in LAOG research, in particular for developments in interferometry. It has
provided a large competitive grant in 2003 (“BQR”, or “Bonus Qualité Recherche”) for optical fiber feeds, and
is a strong supporter of a new project (referred to as “INTERPHAST”), set to occupy in the 2007-2008 time
frame a large area (nearly 2000 m 2 in all) in the CERMO building adjacent to LAOG and IRAM. This project
(mainly funded by the Rhône-Alpes region: 1.5 ME) includes:
• (i) the creation of a LAOG-IRAM European Center of Expertise for Interferometry in Astronomy (CEXIA),
a scientific data analysis center based around the VLTI/JMMC for LAOG on the one hand, and the ALMA
Regional Center project for IRAM, on the other;
• (ii) a new Campus Center for Intensive Computing, extending the one already existing and currently hosted
by LAOG (used not only by LAOG astrophysicists but by other researchers on campus in need of high-speed
and massive computing, especially on grids);
• (iii) a new “Joseph-Louis Lagrange Center for Physics and Astrophysics” for workshops and international
collaborations (inspired by the Lorentz Center in Leiden or ISSI in Bern).
LAOG also has ties at various levels with other laboratories and institutes in the Grenoble area: INPG,
IMEP, CEA-LETI etc. for instrumental research, LPSC and CRTBT for astroparticle physics and cosmology
(“CosmAlp” collaboration). Without going into details, suffice it to say that LAOG is fully conscious of
the richness of the technological and scientific environment of the Grenoble area, and seizes every significant
opportunity of local collaborations or knowledge transfer, including towards the industry (see below).
1.3.4 The European dimension of LAOG
LAOG members are obviously involved in many international scientific collaborations (see details in the team
parts III to VI) . In this section, we want to emphasize the ever growing involvement of LAOG in European
programs and collaborations, first at a “traditional” institutional level (through large agencies like ESO and,
to a small extent so far, ESA, see details in the team reports), but mostly, and increasingly, with the European
Commission “Framework Programs” (FP).
This is illustrated by the following evolution. When the previous report started (1999), LAOG was a node
of a 7-laboratory FP5 “Research and Training Network” (RTN), entitled “Structure and Evolution of Young
Stellar Clusters”. This RTN ended in 2003. The main scientific objective was to gather a significant part of
the European expertise in star formation, and bring together researchers and students spanning all the range
of activities: observations, theory, numerical simulations, etc. (For reference, this network hired 11 post-docs
29

and published 95 papers in four years.)
Currently, under FP6, LAOG is a node for two RTNs (“JetSet” and “Molecular Universe”) and a recently
approved “Large Infrastructure” network (“Arena”, or “Astronomical Research Network in Antarctica”). In
brief:
• JetSet (Jet Simulation, Experiment, and Theory; PI T. Ray, Dublin.) This RTN (2004-2007) aims at
a better understanding of the physics of jets from young stars. Its originality stems from the fact that it
brings together researchers that never worked together before: astronomers (observations), theoreticians (plasma
experts), numericists, and experimentalists in fluid dynamics. All three thematic teams of LAOG have members
in this network; its activities will be described in more detail in the FOST part.
• Molecular Universe (PI X. Tielens, Groningen.) This RTN (2004-2007) brings together astronomers,
modelists and experimentalists, as well as astrochemistry theoreticians, to better understand the physics and
chemistry of the dense interstellar medium, all the way from molecular clouds to protostellar collapse and
protostars. With its specific composition of experts both in mm-wave astronomy and theoretical chemistry, the
Astromol team will bring a strong input into this network (see the Astromol part).
• ARENA (Astronomy Research Network in Antarctica; PI N.Epchtein, Nice) This is a so-called “Large
Infrastructure” network (2005-2008), with the goal of investigating the possibility to conduct intermediate- to
large-scale astronomical projects using the French-Italian permanent scientific station “Concordia” at Dome C.
LAOG is interested by the possibility to contribute to a medium-size interferometer. More details are given in
the GRIL chapter.
LAOG is also involved at high level in three “Joint Research Activities” (JRA) of “Opticon”, a large
European, EC-funded collaboration:
(i) adaptive optics (JRA1, Project Scientist: J.-L. Beuzit);
(ii) interferometry (JRA4, PI: A. Chelli);
(iii) detectors (JRA2, PI: Ph. Feautrier).
These JRAs are also described in more detail in the GRIL part.
Within FP6, LAOG is again competing for a post-Young Stellar Clusters 12-laboratory RTN (“Constellation”;
PI M. McCaughrean, Exeter), and will also compete for new Opticon funding (“Key Technologies for
Astronomy”) in FP7 (starting in 2007).
In addition to these network activities, which bring post-docs (RTNs) and a very significant funding (JRA),
LAOG has a long-standing partnership with ESO (delivery of major instruments for the VLT), and with CNES
and ESA (R&D contracts for Darwin, see details in the GRIL part; high-level involvement in the guaranteed
time program of Herschel, see details in the Astromol part).
1.3.5 Publicizing LAOG’s research: outreach and patents
Part of our web site is accessible to the general public. But this is just the tip of the iceberg, and LAOG is
very active in promoting astronomy to a wide audience. Among the various public outreach actions undertaken
these last few years, we can mention the following:
• Actions in the LAOG building: weekly night observing sessions with our 40-cm telescope on its domed-roof,
first initiated by Manuel Forestini), regular visits of the lab by high-school students;
• Actions within OSUG: For promoting astronomy to a wide audience, the collaboration with other laboratories
of OSUG is very efficient and many actions have a common organization. For example, this is
the case of the ”Fête de la Science”, organized each year in October at a single location for all OSUG
activities.
• Actions on the UJF campus: construction of the “Sentier Planétaire” (the Planetary Path), a scale model
of the solar system on the ground a few hundred meters in size (also initiated by Manuel Forestini);
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organization of astronomy events like the transit of Venus in June 2004 which attracted ∼ 2,000 visitors
and featured an Internet link to New Zealand projected on a wide screen; contribution to a laser version
of the Fizeau experiment for measuring the speed of light, in the framework of the World Physics Year
’05;
• Actions on a national scale: public conferences by various LAOG members, interviews, consulting for
popular astronomy journals, etc.
LAOG’s research is also beneficial for the industrial world. In the past years, we have deposited five patents:
• ”Dispositif d’actionnement électrostatique miniature et installation comprenant de tels dispositifs”, European
Patent, CNRS/CEA, FR0206293 from 23/05/2002. Patent holders: J. Charton and E. Stadler.
• ”Composant MEMS électrostatique permettant un déplacement vertical important”, French patent, CNRS/CEA,
FR0351211 from 26/12/2003. Patent holders: J. Charton and C. Divoux (CEA/LETI).
• ”Miroir déformable magnétique”, French Patent, CNRS, FR0452342 from 12/10/2004. Patent Holders:
J. Charton, Z. Hubert, L. Jocou, E. Stadler, P. Kern and J.-L. Beuzit.
Two applications are currently proceeded in the frame of our activities on future detectors:
• ”Détecteur et caméra spectroscopique interférentiels”, French Patent, UJF INPI 04/52992, applied December
15th 2004. Patent Holders: le Coarer, E., Benech, P.
• ”Spectrographes à onde contra-propagative”, French Patent, UJF INPI 05/08429, applied August 8th
2005. Patent Holders: le Coarer, E., Benech, P., Blaize, S., Kern, P., Lérondel, G., Morand, A.
More details are given in the GRIL part.
1.4 Budget: resources
LAOG’s operating budget resources can be broken down in five sources, for a total of ∼ 400 − 500 kE/yr. Their
respective contributions are illustrated graphically in figure 1.7 for the period 2001-2005. We now comment
these funding sources in turn.
• “Recurrent” funds, i.e., operating budget from the Ministry of Education and CNRS, on a four-year
basis (the “quadriennal contract”). 3 As figure 1.7 shows, in rough terms this funding accounts for about
half of the total operating budget, so it is a very important contribution that should be adequately adjusted
to the laboratory demographic evolution. Over the 2002-2005 period, this has in fact been approximately
the case (∼ 20% increase).
• “Specific” budget, mainly from CNRS but also UJF (competitive “BQR” = Bonus Qualité Recherche).
Basically, this budget follows that of the Ministry of Education, but sometimes one can obtain exceptional
dotations (boost for a newly accepted project, replacement of an old laboratory car, etc.). It is mainly
used for R& D activities, i.e., it is an investment corresponding to the scientific policy of LAOG to develop
research for future instruments which are not yet funded, by definition. This line has fluctuated by more
than a factor 2 (between 75 kE and 180 kE) depending on the circumstances: for instance the largest
amount corresponds to a UJF BQR of 60 kE in 2004.
3 Note for our foreign members of our Visiting Committee. The level of funding results from the conclusions of the Evaluation
Committee (the present exercise). It is based on a sum per capita (permanent researchers only; publishing engineers and nonpermanent
staff like students of post-docs are not taken into account), which is calculated on the basis of publications, times a
certain coefficient reflecting the quality of the laboratory, and is ultimately negotiated between the Ministry of education and the
local university, UJF in our case.
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• National astronomy programs. 4
Figure 1.7: Budget resources structure
The main programs of interest for LAOG are PNPS (Programme National de Physique Stellaire), PNP
(Programme National de Planétologie), and PCMI (Programme National de Physique et Chimie du Milieu
Interstellaire), along with the GDR (research cluster) PCHE (Physique des sources Cosmiques à Haute
Energie) and the ASHRA (Action Spécifique pour la Haute Résolution Angulaire). The corresponding
funds are used essentially for collaborative purposes (in some cases also for equipment), mainly, though
not exclusively, within the French community. A yearly AO is issued, followed by a selection of proposals
by a scientific committee.
The funds made available through National Programs bring about 20 to 30 kE, (with fluctuations since
the funding of the National Programs is itself variable). They can provide very useful “pocket money”
to the teams for collaborations (∼ 10-15% of the total LAOG operating budget). For their parts, LAOG
teams are regularly successful, and use these funds as much as possible to have an independent budget
which they manage by themselves, mainly for scientific collaborations, including short-term visitors, and
thematic workshops.
This year (2005) a new national research funding structure has emerged, the “Agence Nationale de la
Recherche” (ANR). Basically, this structure (endowed with about 700 ME in total), more or less inspired
by the NSF, is meant to provide funds and human resources (which is a major difference with national
programs) on a competitive basis. While most of the funding is targeted towards major national priorities
(e.g., nanotechnology projects), a fraction (about 20 %) is “open”. ANR issued its first AO last spring,
and LAOG has submitted several proposals in the open category, mostly for post-docs (a critical deficiency
of the French research system). Thus the funding LAOG competes for with ANR is roughly an order of
magnitude larger than for programs –which is logical since salaries are now counted. We are expecting
the results of this new experience, which could have a strong impact on our future funding.
4 Another note for our foreign colleagues. French research in astronomy is structured into “national programs” or smaller-sized
“research clusters” and “specific actions”, funded mainly by CNRS, with contributions from other state agencies like CNES (French
space agency) and CEA (Atomic energy commission).
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• Contract-related funding. These funds are obtained as a result of successful proposals after an AO
has been issued: these can be contracts with an international institute (like ESO), or with industry (e.g.,
Alcatel Space). In some cases, after the contract is awarded, an additional contribution (typically from
CNRS/INSU) can be obtained, for instance if there was a share of the costs between the international
institute and the country of the successful proposer (e.g., VLT instrumentation). These contributions are
known respectively as “Contracts” and “Operations” .
However, care must be taken in entering these funds into the laboratory budget. Indeed, a contract, by
construction, is a box in which funding comes for a specific purpose: it is spent for that purpose only (for
instance to buy equipment or instruments), and only overheads can be used to contribute to the operating
budget of the laboratory as a whole (furniture, missions, etc.). For such contracts, LAOG typically retains
10% of their amount for this purpose. It is this “tax” that must be added to the previous funds, not the
amount of the contract itself. (One should add for completeness that some contracts do include salaries,
but this is currently more the excpetion than the rule, and in view of the present budget exercise the
salaries have not been taken into account for the sake of clarity.)
Therefore, in figure 1.7 we have included only these 10% (referred to as “contributions” in the figure),
and not the full amount of the “Contracts” and “Operations” (which is thus simply 10 times larger). As
a result, and contrary to what might naively think, even though the contracts themselves may look large,
(like 350 kE for WIRCAM at CFHT), the total amont effectively usable for LAOG common expenses is
not so large (30-70 kE/yr, i.e., less than “specific” funds, or ∼ 15-20% of the budget).
In this way one arrives at a realistic operating budget, comprised between 400 and 500 kE/yr. (If contracts
are used fully instead, one obtains an enormous year-to-year vartiation: 1200 kE in 2004 vs. 650 kE in 2005,
which obviously does not reflect at all the way the laboratory operates on a day-to-day basis.) This is perhaps
the good news. The bad news is that when one divides this amount by the LAOG population, one gets a very
significant decrease of funding as a function of time. This is illustrated in figure 1.8, which displays two parallel
histograms. The histogram with the largest boxes shows the operating budget per capita if one counts only the
permanent staff (36 in 2001, 43 in 2005), the smaller boxes if one counts the whole population effectively present
(i.e., including PhD students, post-docs, etc.: 76 in 2001, 98 in 2005). The figure also displays a regression line
for the two histograms: the decline is obvious, on the order of 20% over five years (more like 30% if one takes
inflation into account), with admittedly fluctuations on the order of 10% due to start and end of contracts.
Figure 1.8: Time evolution of the operating budget per person (in kE). Large box histogram: counting permanent
staff only. Small box histogram: counting all LAOG members (including PhD students, post-docs, etc.).
Pending a new way of operating with the ANR in the future, the most obvious solution would be to look
for more contracts. But this is misleading: (i) doubling the amount of contracts would bring not more than
another 10 %, and only to 15-20 % of the operating budget ; (ii) more importantly, LAOG basically has one or
two large contracts per “quedriennal”, corresponding to the instrument plans of agencies like ESO, and this is
the best it can hope for given its mission to do fundamental research, and not look for large-scale applications.
The other solution is to reinforce significantly the “recurrent” funding, since, as noted before, it amounts to
about half of the LAOG operating budget.
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1.5 From dreams to reality: Human resources
Contrary to the funding situation, LAOG has been fortunate in getting a significant number of permanent
positions for researchers, while the ITA population has remained stable (22). Over the 2002-2005 period, LAOG
had 3 fresh CNRS positions, 2 astronomers, and 1 UJF assistant professor (unfortunately just compensating
for the loss of M. Forestini). Overall, LAOG remains a young laboratory, not only because of a comparatively
recent creation, but also because of the number of young researchers and engineers.
This is testified by the demographics (see figure 1.9): the average age of permanent researchers is 44,
while, even more remarkably, the average age of engineers and technicians is 40. In passing, we note that as a
consequence most of the actors of the present prospective exercise will be able to conduct the proposed projects,
even very long-term ones, themselves if they want to. This is a truly fortunate situation among similar-sized
laboratories in France.
Figure 1.9: LAOG age histogram
Another asset of LAOG is its Technical Group, headed by P. Kern. Operationally distinct from GRIL, but
sharing with it all of its engineers (14), backed by 6 assistant-engineers and technicians, this Group has the
major responsibility to build instruments and make them work and used by the community. Its role is illustrated
in the new LAOG histogram (see Figure 1.3). More details on its structure and internal organization are given
in Appendix in chapter 18, and its impressive record in building instruments for ESO and CFHT, is described
in the GRIL part.
1.6 The 2007-2010 prospective and beyond
1.6.1 Main scientific objectives
Any scientific prospective spanning a rather long period (2007-2010 is just a step towards a longer term future)
is a somewhat risky exercise because on many unknown external factors. Most importantly for LAOG, future
projects of major agencies like ESO or ESA and their funding include highly political factors like the developments
and future science priorities in France and in Europe, but we can at least describe LAOG’s objectives
given the current general context.
The present structure of LAOG in four teams has, among others, the advantage of allowing to streamline
the main scientific issues and questions. Given the expected progress and projects, these can be synthesized as
follows.
• From local to global star formation. A major topic will remain the formation of solar-type stars,
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in relation with planet formation. Currently unsolved problems involve the exact nature of gravitational
collapse: what is the leading factor, magnetic fields or turbulence ? The physico-chemistry of protostellar
envelopes and young protoplanetary disks, with a whole array of spectral diagnostics down to the innermost
regions (< 1 AU), will give us precious indications about the velocity field and extent of the accretionejection
phenomenon, the density and temperature conditions, the existence and abundance of possible
prebiotic molecules, etc. The advent of Herschel (to be launched in early 2008) will allow LAOG to
attack these questions with sophisticated chemistry and radiative transfer models to identify and interpret
thousands of spectral lines. ALMA will later expand the result at high spectral resolution; however the
spectral line diagnostic will be unable to include the lines that are undetectable from the ground. Currently,
ALMA is not expected to be operational before 2012, so within the current prospective a major effort will
be devoted by the Astromol team to the interpretation of Herschel data, while increasing the involvement
in existing facilities like the IRAM telescopes (single-dish 30m and PdBI interferometer), JCMT and
CSO in Hawaii, APEX in Chile (a precursor to ALMA antennae). A complementary view, mainly for
comparison with the early solar system, will be offered by the laboratory study of irradiation effects by
high-energy photons and particles emitted by the central protostar.
At later stages, other issues related to global star formation emerge, also on the FOST side: e.g., why is it
that star formation occurs in cluster mode and in isolated mode; more generally in so many different modes
(including starbursts in galaxies for instance); what is the origin of brown dwarfs, and in particular of the
“free-floating” low-mass objects far from star-forming regions ? To what extent is the IMF universal ?
The FOST teams attacks some of these problems with modern tools like N-body simulations and extended
surveys at CFHT like CFH12K and WIRCAM KP surveys of young open clusters, or extended nearby
star-forming regions like Taurus.
• Disk evolution and planet formation. One of the most exciting challenges of modern astronomy,
with many deep implications like the universality of life, is to know whether the solar system is typical or
exceptional among all planetary systems. Two different approaches can be considered.
(i) On the one hand, to understand whether and how planets (especially terrestrial planets) form as the
ultimate phase of evolution of circumstellar disks around young, solar-type stars. This requires an indepth
study of the evolution of disks, from their young stages dominated by accretion and correlated jets,
to later stages where dynamical interactions (instabilities, companions, etc.) deeply affect the growth of
dust grains into planetesimals and planets, over timescales of ∼ 10-100 Myr. While LAOG currently is
not directly involved in the study of planet formation per se, it is certainly in an enviable place to obtain
constraints on prevailing physical conditions, and on the history of disk structure evolution (gaps, rings,
spirals, etc.) from observations and models.
(ii) The other approach is to consider already formed exoplanetary systems. With a sufficiently large
sample (hundreds ?) of planetary systems down to the lowest possible planetary masses (Earthlike,
ideally), one can start to apprehend the rules and the exceptions, in comparison with our solar system.
The current arsenal of exoplanetary search consists of a majority of radial-velocity (stellar reflex motion)
detection (30 of them have a LAOG member as co-discoverer), and of a handful of transits in front of
the host star. Apart from the only confirmed (so far) recent detection of a planetary mass object around
a brown dwarf (a situation hardly comparable to the solar system), no direct imaging of exoplanets is
currently available. The development of instruments able to bridge this gap will open an entirely new
era –if only because systems with orientations at large angles to the line of sight will become detectable,
significantly enriching the parameter space for exoplanetary systems and putting new constraints on their
origin.
With the Astromol and FOST teams, LAOG has the expertise to have these two ends meet and study
how well (or how badly) these two approaches may converge, in particular with the new instrumental
projects (see below) it is leading. In short, at the horizon 2010 LAOG hopes to make radical advances in
our current understanding of star and planet formation, with the ultimate goal to pin down the connection
(or lack thereof) between exoplanetary systems and our solar system.
• The close environment of accreting objects, from black holes to young stars. As its core activity,
over the term of the present prospective (2010) the SHERPA team will focus on the physical processes that
take place in the close environment of Black Holes. This includes the analysis of the gross phenomenon
combining MHD and gravitation, to high energy radiation and astroparticle physics, via the turbulent
transport theory and the kinetic theory of relativistic plasmas and particle acceleration. These theoretical
developments will be applied to various physical environments: the Blazar phenomenon (stratified models,
variability); micro-quasars (“two-flow” paradigm, modelization of the changes of state); signatures of the
Kerr metric in the phenomenology of AGNs and micro-quasars; instabilities and turbulent transport in jets
35

and accretion disks with heavy numerical MHD simulations; and relativistic plasma physics: reconnections,
shocks and flows (for Blazars, micro-quasars and Gamma Ray Bursts).
Some branch activities will continue in parallel: accretion-ejection phenomena in young stellar objects
(numerical simulations of the interaction between the stellar magnetosphere and the accretion disk);
astrocladistics (innovative classification method of galaxies in relation with the issue of AGN formation
by merging). Also, the team will continue developing connections with High Energy Experiments (XMM,
INTEGRAL, GLAST, SIMBOL-X, HESS etc.) and with the LAOG observing facilities (VITRUV, ...).
Over the longer term (2015), the Sherpas team expects to be involved in the theory of transitory signals
from Black Hole environments that will be recorded simultaneously by different kinds of astroparticle
experiments, revealing different but correlated aspects of their phenomenology. This will involve gammaray
transient emissions, neutrino bursts and gravitational waves. The main sources of such combined
events will be the double quasars. The Pierre Auger Observatory for UHE cosmic rays will also be an
important source of informations for AGNs and GRBs physics, as well as for the knowledge of the cosmic
magnetic field.
• Instrumental developments: towards higher angular resolution and higher dynamic range.
The instrumental activities for the present period have been dominated by the delivery of two major
NIR (JHK) instruments for ESO’s VLT: the large adaptive optics system NAOS, and the interferometric
recombiner AMBER, as well as the WIRCAM wide-field NIR camera for CFHT. While these instruments
are already successfully working, they show that the present goals of LAOG cannot be fully obtained
with them: if one wants to really understand the formation of planetary systems, one needs to reach a
linear resolution of 1 AU or less at 150 pc (the typical distance of low-mass star forming regions), which
translates in a 6 mas spatial resolution; if one wants to image planets close to their host star, i.e., within
the first diffraction minimum, a tremendous dynamic range is required (∼ 10 −6 ).
To face these challenges, LAOG has embarked in two major projects for ESO’s 2nd generation of VLT
instruments, which will draw the majority of its engineering manpower (15 FTE) for the period 2007-2010:
• (i) The VLT-PF (“Planet Finder”) project, which is now in the final stages of approval. LAOG
led a European consortium which was selected by ESO in 2005 over a competing one. Compared to NAOS,
the main emphasis is on a very high dynamic range (∼ 3 × 10 5 at 1 Airy radius, or at ∼ 20 mas at 1 µm for
an 8-m telescope), to reach the scientific goal of direct detection of dozens of Jupiter-mass planets, possibly in
multiple systems (as a few are already known from the radial-velocity method). It is expected to be completed
in 2009-2010. This will pave the way to future spectroscopy of these planets, and eventually of Earth-like planets
(Darwin project, post-2015, see below).
• (ii) The VITRUV project. Proposed to ESO which may reach a decision in 2006, this is currently
an in-house LAOG project for the 2nd generation VLTI. It basically consists in a large interferometric beam
recombiner making use of integrated optics. Its ultimate goal is to use all 8 Paranal telescopes (4 UT and 4 AT)
to make up one of the world’s largest optical/IR interferometer, with a maximum baseline of 200 m. This will
allow to reach the maximum possible angular resolution of ∼ 0.5 mas in the visible range, allowing for instance
to probe the inner regions and fine structure of circumstellar disks of young stars and AGNs and their jets, i.e.,
to probe in unprecedented detail the “central engine” of the accretion-ejection phenomenon in a wide diversity
of environments.
Therefore, the main challenge for LAOG resources will be to manage two important projects (if VITRUV
is approved) over the same time frame, while continuing R&D activities. Details about other projects under
consideration can be found in the GRIL chapter.
To help in the interpretation of increasingly complex observations, LAOG is also investing significant efforts
to contribute to the Virtual Observatory (VO). In its present stage, the VO offers an easy and interoperable
access to the astrophysical data (spectra, images, etc) gathered by the major observatories all over the world
and to the corresponding publications and tables. This huge work is the fruit of an unprecedented international
collaboration, through a hierarchy of working groups and institutions – with special mention in France to the
CDS in Strasbourg and to the recent “Action Spécifique Observatoire Virtuel” of INSU. Our objective is to
enrich the VO with original services. Most tools developed at the JMMC (as already done for SearchCalib)
will be interwoven to the VO for an optimal preparation and calibration of observations. Also, theoretical
developments will be offered to the VO. Inelastic collisional rates computed in the ASTROMOL team (including
the corresponding milestones for the “Molecular Universe” RTN framework) will be included in the advanced
36

BASECOL database hosted in Meudon to feed line data analysis requests with the latest data. Corresponding
simple and pedagogic VO services (e.g. at LVG level) will be developed for the non specialist user with error
bars and warnings.
1.6.2 Long-term strategic questions for LAOG
The world’s astronomical panorama is evolving fast, and long-term instrumental projects are already at the
discussion or even R&D stage. LAOG has already been contacted to participate in some of these projects.
The main challenge for LAOG is to keep in focus its scientific goals, and to give a weighted priority to its
participation to any long-term project depending on how these goals may be fulfilled. While, as we have seen
at length, LAOG has definite projects for the 2007-2010 time frame, it also has to consider them within a
longer-term perspective, out to 2015 or even beyond.
While the list of opportunities may evolve, and no definite decision can be taken now, the current strategic
issues under discussion at LAOG are the following.
• Extremely Large Telescopes. There are several studies around the world to dramatically increase
the size of current telescopes by use of segmented mirrors. ESO, for its part, is pushing the OWL
(“OverWhelmingly Large”) telescope project. The target diameter is 100m, but feasibility studies may
reduce it to 30m. Whereas cosmologists push towards the largest possible sizes in order to collect photons
from the youngest possible galaxies, recent studies seem to indicate that beyond a diameter of 30m no
significant gain (in terms of a sensitivity vs. contrast compromise) can be expected for exoplanet science.
However, should the larger size be decided, there are ideas (in particular within LAOG) to use selected
mirrors of an ELT to make up an interferometer within the telescope itself, with an unprecedented, almost
continuous coverage of the uv plane.
• Astronomy in Antarctica. The fact that the French-Italian Concordia scientific station has recently
been completed at Dome C has given a boost to astronomical projects in Antarctica. Located deep
within the Antarctic plateau, at 3200m altitude in a very dry and stable atmosphere, Concordia is able
to provide a permanent logistical support, even in winter, for a dozen scientists of all disciplines. LAOG
participates in a recently approved EC-funded “Large Infrastructure” FP6 project (ARENA, see above),
which aims at investigating in detail the feasibility of establishing a European astronomy facility, including
an interferometer, at Dome C. Up to now, LAOG is involved modestly, mostly for scientific support (for
instance, a question to address: is Dome C a better location than Paranal for star and planet formation
issues ?). The rumours according to which ESA is currently studying the idea of putting the GENIE pre-
Darwin nulling interferometer at Dome C rather than at Paranal, under an adapted form (ALLADIN),
may change the situation: in view of its current involvement in Darwin R&D studies (see below), LAOG
is ready to adopt the view that, in addition to doing its own science with it, an ALLADIN-type project
can indeed be an important step towards a major space interferometer like Darwin. This will however
require extra manpower not currently available.
• Going out to space ? Darwin. This is an ESA “Horizon 2000+” program cornerstone. It will not
fly before 2015. Its primary scientific goal is extremely ambitious and difficult: to find evidence for
extraterrestrial life by detecting ozone lines (the currently accepted major tracer of life) on Earth-like
planets. This will be done with a 4-spacecraft nulling space interferometer (3 independent telescopes and
a recombiner, the whole array being controlled by laser beams), i.e., blocking with an extreme efficiency
(contrast of ∼ 10 −9 ) the light of the central star. This is arguably a formidable technological and scientific
challenge. While LAOG does not yet have its own expertise in exoplanetary atmospheres (drawn elsewhere
from solar system planetary and brown dwarf atmospheres), it is clear that it already has a strong longterm
scientific interest in Darwin. It has already manifested this interest by participating to the scientific
group of “Pégase”, a Darwin precursor space interferometer proposed to CNES, currently in competition
for a pre-Phase A study. The ozone lines to be detected being in the mid-IR range, it is critical for Darwin
to be able to recombine beams in this wavelength range. The recent result obtained by LAOG, after several
years of research under ESA/CNES/industrial R&D contracts, to guide 10 µm waves for the first time,
represents a breakthrough towards building a recombiner for Darwin. LAOG is seriously considering
boosting these instrumental efforts and will have, in parallel, to develop collaborations and/or its own
scientific expertise in planetary atmospheres in the next decade, to be able to reap for itself the scientific
benefits of this exciting adventure. It is noteworthy that the present LPG prospective includes a new
37

emphasis on the chemistry of planetary atmospheres, with an explicit goal to be involved in exoplanetary
atmospheres by 2010. While LPG is concerned on the short term with solar system objects (mostly Titan,
in relation with the Cassini-Huygens mission), LAOG (Astromol and/or FOST) will have discussions
about possible common scientific goals for exoplanets in the same time frame, in preparation for Darwin.
• Other space missions ? Over the long term, LAOG may also consider a greater instrumental involvement
in telescopes that can only be put in space, while keeping within its scientific priorities: high-energies,
and submm astronomy. The projects that one can consider would be mostly with CNES or/and ESA.
In the high-energy, hard X-ray domain, the Sherpas team is already involved (for AGNs and compact
binaries) in the scientific group around Simbol-X, a two-satellite proposal led by CEA Saclay (which is
competing, along with Pégase, for a CNES-funded pre-Phase A study), but no instrumental development
is currently foreseen at LAOG. In the 2015 timeframe, i.e., the same as Darwin, the XEUS project, successor
to XMM, is the leading high-energy project within ESA. LAOG might be more involved in the project
(which has strong support from space laboratories in France), but again likely not at the hardware level.
In the submm domain of interest mainly for Astromol, Herschel, to be launched in 2007, will require many
years of scientific exploitation. Its only currently identified long-term successor in ESPRIT, but with no
date set for launch. On the other hand, there are already also here some thoughts about Antarctica (the
most interesting domain is the THz range). Here again, there are no current plans for a LAOG hardware
involvement, but it has to stay alert to possible evolutions.
1.7 Conclusions: A vision for the post-2010 future of LAOG
By 2010, because of the important scientific results it has already obtained, and its successful bids to build new
major instruments for the VLT, it can reasonably be expected that LAOG will have the following ambitious
objectives for the next decade. But it has to grow again to accomplish them...
• The VLT-PF and, hopefully, VITRUV will be completed and start operations at the VLT. This means
that in the mean time, most of LAOG’s scientific results will be obtained with existing instruments,
mostly at the VLT (with instruments it contributed to build or other Paranal instruments), and at CFH
(exploitation of WIRCAM). A much better knowledge of the evolution of circumstellar disks, over a time
span of ∼ 1 to ∼ 100 Myr, is expected from instruments like NAOS or AMBER. Along with work on the
evolution of early solar system going on elsewhere (and at LPG in particular), the hope is that by 2010 we
will know as much (or as little ?) about planet formation as we know about star formation today. Several
hundreds of exoplanets, and possibly several tens of exoplanetary systems will be known, some containing
Earth-like planets. Even though the VLT-PF has the main goal of imaging Jupiter-sized planets close to
the host star, the recent images of the brown dwarf-exoplanet system 2M1207 demonstrate that several
systems will certainly be imaged before the VLT-PF becomes available. On the other hand, studies will
have matured at LAOG to contribute to building some kind of ELTs and/or single telescopes and possibly
an interferometer in Antarctica, as well as contributing to the Darwin recombiner. The participation of
LAOG to all these ventures will ensure activities of LAOG in the field of star and planet formation well
into the next decade. But such ambitious goals require a significant increase in manpower in the coming
years: 3-4 researchers for FOST, 3-5 engineers and technicians for GRIL and the Technical group.
• The Herschel mission will be operational right into the present prospective, and thus, by opening a new
window in the universe, will constitute the newest branch of submillimeter astronomy, with a rich harvest
in spectroscopy and key results on star formation and early evolution. On the ground, IRAM telesscopes
will play a pivotal role, at least until ALMA starts operations (hopefully in 2012), along with other existing
(sub)millimeter telescopes elsewhere. Already a significant part of the astronomical activities related to
star formation is dedicated to the search for prebiotic molecules, as part of a worldwide effort to develop
exobiology. As explained in the prededing sections, the Astromol group is particularly well placed to
pursue these lines of research. However, the task is daunting, and the Astromol team has to grow, and
grow fast, since a few of its members will have retired by 2010. Hiring, and/or attracting at least 2-3
permanent researchers in the coming years is absolutely vital for Astromol.
• A (tentative !) picture appears from combining three factors towards 2010: (i) development of exoplanet
research in the FOST team; (ii) developments in the search for prebiotic molecules, and also in theoretical
chemistry in the Astromol team; (iii) the planned developments in the chemistry of planetary and
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exoplanetary atmospheres at LPG. This picture is the emergence of what might be called (in analogy
with cosmology): observational exobiology, i.e. obtainining astrophysical and astrochemical diagnostics
for contraining the conditions for the emergence of life in other planetary systems. This would be an
extraordinary preparation for LAOG (in addition to its possible instrumental developments) and LPG
to be really involved in the scientific exploitation of the Darwin mission. This could conceivably lead
to create at that time a new team: S2E (Science des Exoplanètes et Exobiologie: Exoplanetary Science
and Exobiology), possibly a joint venture of LAOG (researchers from FOST and Astromol ?) and LPG.
(Close contacts with the CRAL group in Lyon, which is already very strong in brown dwarf and planetary
atmospheres, should also be developed.)
• On the high energy side, the adventure is no less exciting. As explained in the Sherpa prospective, the next
decade will see the coming of age of an entirely new generation of telescopes, opening non-electromagnetic
windows on the universe: gravitational waves and neutrinos. This will be the time of a radically new
approach to the physics of black holes. Already the Sherpa team is exploiting data from high-energy
telescopes both on the ground (HESS) and in space (X-ray and γ-ray satellites). Theoretical developments
will require to explore new fields of physics and involve more and more numerical simulations. The goal
of the Sherpa team is to hire 2 researchers in the coming years. What is not clear at present (but we
have some time to think about it) is whether the Sherpa team will keep the close ties it has today with
the rest of LAOG and still invest part of its efforts in the (more conventional ?) physics of young stars
and planets: its expertise in magnetic fields and plasmas could still to be the common ground.
We started this report by emphasizing the youth and fast growth of LAOG. We hope the reader is now
convinced that there is currently no reason to fear a “growth crisis”, and that LAOG will be able to be up to
the scientific challenges it wants to take. In total, it strongly hopes to hire or attract 7 to 9 new researchers,
and 3 to 5 new engineers and technicians by 2010. Unless there is a crisis in funding (as was nearly the case in
2003), LAOG, in its local, national, and international environments, can only expect a bright long-term future.
39

Part III
TEAM ASTROMOL
Sub-arcsecond image of a complex organic molecule in the proto-binary system of
IRAS16293-2422
41

Chapter 2
Presentation and Scientific Objectives
2.1 Presentation of Astromol: composition, goals and summary of
activities
The Astromol team was created in January 2003, with the new organization of the LAOG structure. It results
from the merging of the group working on Theoretical Molecular Physics with the group working on Star
Formation (born from the previous group
on the Interstellar and Circumstellar Medium). Both groups are mostly newly formed, by accretion from
different observatories and laboratories as well as by members originally from LAOG. Table 2.1 lists the staff
members of Astromol: nine researchers, three of whom are teachers at UJF, one is Astronome at UJF, and five
are CNRS/CEA researchers.
Name Grade Specialty
J-J. Benayoun Professor UJF Astrophysical models
C. Ceccarelli Astronome Astrophysical obs and models
F-X. Desert a Astronome Astrophysical obs
A. Faure CR2 Molecular Physics
C. Kahane Professor UJF Astrophysical obs
B. Lefloch CR1 Astrophysical obs and models
T. Montmerle DR1 Astrophysical obs and models
C. Rist Maitre de Conf. Molecular Physics
P. Valiron DR2 Molecular Physics
L. Wiesenfeld CR1 Molecular Physics
Table 2.1: List of the permanent staff members belonging to the Astromol team and their respective expertise.
a Note that Desert joined Astromol team during 2005: his activity is described in §4.5.
The goal of the Astromol team is the study of the physical and chemical proprieties of the inter-stellar and
pre-stellar matter, by a tight coupling between the theoretical and observational approaches. One major goal
for Astromol is the study of the chemical and physical evolution of solar type stars in the first phases of their
formation: from the first steps leading to the gravitational collapse -Pre-Stellar Cores- to the proto-planetary
disk phase.
To achieve our goal:
• we carry out observations at the large radio to sub-millimeter ground based telescopes, as well as space
based telescopes in the FIR, NIR and X-rays wavelengths;
• we develop models to solve the line formation, radiative transfer and chemical composition problems;
43

• we develop quantum and classical formalisms in molecular physics, relevant to the understanding of the
physics and the spectra that we observe;
• we compute theoretical molecular physics data, developing and using state of the art ab initio quantum
chemistry codes as well as dynamical calculations.
Astromol is, therefore, composed of people having very different skills and backgrounds: astrophysical observations,
astrophysical modeling, ab initio molecular calculations, and theoretical molecular physics. In the
following we will refer to the two major activities of Astromol as the Star Formation and Molecular Physics
respectively. Figure 2.1 shows the logical scheme of the interaction between the astrophysical and the molecular
Figure 2.1: The activities of Astromol and the synergy of the different components. The logical sequence
is as follows: 1- we select the target of our study; 2- we do observations of the target object; 3- by using
the collisional coefficients relevant to the observed molecule, we interpret the observations deriving the temperature,
density and chemical composition of the studied object, by means of theoretical radiative transfer
models; 4- by using the rates of the chemical reactions we build a chemical model; 5- finally, we reconstruct the
physics/dynamics/chemistry of the target of our study.
physics expertise of Astromol members, taking the example of the study of a solar type forming star. In order to
understand the star formation process one needs to reconstruct the physical, dynamical and chemical structure
of the matter, as function of time, namely as this structure evolves during the formation process. One of the
best tools for this study are the lines emitted and/or absorbed by the gas, because:
i) lines intensities (either in emission or in absorption) depend on the gas temperature and density, and, for this
reason, multi-frequency line observations allow to reconstruct the density and temperature profile of the gas;
ii) lines from different chemical species allow to reconstruct the chemical composition of the gas;
iii) lines profiles provide information on the kinematics of the studied region.
Given the involved temperatures (between 10 and few hundreds Kelvin) and densities (between 10 4 and 10 9
cm −3 ), molecular lines are the privileged tool for studying forming solar type stars. The sequence in Fig. 2.1
illustrates, in practice, the synergy between the astrophysical observations and modeling, and the theoretical
molecular computations. Astrophysical observations and modeling motivate theoretical molecular computations;
in turn, theoretical molecular computations feed the astrophysical modeling, and allow the correct interpretation
of the data. In synthesis, the research activity of Astromol may be summarized into a few major axes:
observations at telescopes (§2.2), development of astrophysical models (§2.3), development of molecular physics
theories and codes, plus computation of molecular and intermolecular properties (§2.4). Our research leads
to several publications in international specialized journals, as well as to communications to congresses, both
invited or not (§2.5).
Another important aspect for Astromol is represented by the teaching and student formation, an activity
which absorbs a substantial fraction of the team energy and time, and which is vital for the life of the team
itself (§2.6).
Finally, Astromol is actively involved in national and international activities and collaborations. It is worth
here to mention three large national and international projects, where Astromol is a major actor (see §2.7
for a detailed description): “WAGOS”, “FP6 - THE MOLECULAR UNIVERSE”, and “HERSCHEL SPACE
OBSERVATORY - HIFI”. Regarding the interaction with the “Programmes Nationaux” Astromol is financially
44

supported by PCMI and PNPS, and members of Astromol have been and currently are members of the PCMI
board.
Table 2.2 summarizes the Astromol activities at glance.
Observations at the telescopes Satellite: CHANDRA + XMM +
SPITZER + ISO data reduction
Ground-based: IRAM + JCMT + CSO...
Development of astrophysical models Lines from collapsing envelopes
and LVG codes
Molecular physics: theories and codes Ab initio and collision codes development
Transition state theory.
Intensive computation on National Computer
facilities and local Ciment network facilities
Teaching and students formation 2 Professors + 1 MdC + 1 Astronome
UJF-SD + Master 1 Physics
5 PhD thesis + 5 DEA stages
Publications and communications Articles in refereed Journals: 102
Invited presentations in international
congresses: 24
Collaborations National: FOST, WAGOS, PCMI, PNPS...
International: FP6 “The Molecular Universe”
Herschel-HIFI and ALMA projects, JETSET
Table 2.2: Astromol activities at glance for the period 2002-2005.
2.2 Observations at the telescopes
Astromol members carry out observations with satellite and ground based telescopes, covering a large frequency
range, from the radio to the X-ray.
Satellite telescopes: Astromol members (TM) are involved in the explotation of the two large X-rays telescope
currently in orbit: Chandra and XMM. These facilities, launched in 1999, have allowed to conduct observations
of star-forming regions in two directions: (i) characterization of the stellar X-ray sources, from massive stars to
substellar objects (brown dwarfs: see FOST chapter); (ii) discovery and study of diffuse X-ray emission in HII
regions excited by very massive stars. In turn, this has led, in the context of the Astromol team, to studies of
X-ray irradiation effects (both in the vicinity of young stars and from diffuse emission) on the surrounding dense
molecular medium. SPITZER, a near to far Infrared telescope currently in orbit, is used (BL) to study regions
of massive star formation and the proprieties of the energetic outflows emanating from young protostars. ISO
(the ESA far Infrared telescope in orbit until 1999) data are still reduced and used to study regions of low mass
star formation (CC, BL).
Ground-based telescopes: Astromol members (BL, CC, AF, LW, CK) are heavy users of the IRAM, JCMT and
CSO millimeter and submillimeter telescopes. They also regularly use radio telescopes like GBT (10 hours in
2005) or VLA, though at a less extent. Table 2.3 summarizes the amount of 2002-2005 allocated time at IRAM,
JCMT and CSO telescopes to proposals where members of Astromol are within the first three co-proposers. The
Telescope 2002 2003 2004 2005
IRAM-30m 300 300 363 180
IRAM-PdBI - 1 5
JCMT 128 132 95 330
CSO - 50 90 100
Table 2.3: Time allocated (in hours, except for IRAM-PdBI, where the number of nights are reported) to the
different telescopes used by members of Astromol.
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Table shows not only the volume of the observational activity, but also the trend in the use of the telescopes. It
is worth noting the positive gradient in the use of the CSO and JCMT submillimeter bands, and the net increase
of the use of the IRAM interferometer PdB. Both trends shows how very naturally Astromol is preparing itself
at the best exploitation of the two future big international projects: Herschel and ALMA.
2.3 Development of astrophysical models
Two classes of models have been developed within the Astromol team:
i) Radiative transfer models (CC) that compute the line emission from the collapsing envelopes, for several
molecules (H2O, CO : Ceccarelli et al. 1996, 2003; CH3OH : Maret et al. 2005; SO and SO2 : Wakelam
et al. in prep; HDO : Parise et al. 2005). Astromol (CC, BL) also developed a simple LVG code for the
first level of analysis in more general conditions (like for example outflows). Some results of these models
are made publicly available at the WEB site:
http://www-laog.obs.ujf-grenoble.fr/∼ceccarel/mepew/mepew.html.
ii) Chemical models of star forming regions (CC). We have developed codes specialized in the Sulphur chem-
istry (Wakelam et al. 2004, 2005), in the molecular deuteration due to grain surface (Parise et al. 2005),
and deuterium chemistry of the ion H + 3 in protostellar disks (Ceccarelli & Dominik 2005).
In addition, Astromol members (LW, AF, CC, BL, PV) have undertaken recently a systematic theoretical and
observational survey of the cyanopolyyne family of rod-like molecules, of general formula HC2n+1N. It should
serve as a prelude to several new lines of observations and theories for larger molecules (notably organic complex
molecules) in several types of astrophysical environments.
2.4 Molecular physics: theories and codes
Several classes of new theoretical and algorithmic tools to solve molecular physics problems relevant to astrophysics
are currently developed and used in the Astromol team. They can be regrouped in the following
classes:
i) A quantum chemistry code that takes into account explicitely the correlation cusp between each electron
pair. The fulfillment of this mathematical condition permits to approach the infinite basis set limit at the
coupled cluster level of theory and to achieve an accuracy in the cm −1 range for the interaction of small
non-reactive molecules.
ii) A generalization of the so-called Transition State Theory for inelastic processes. This new method provides
a geometrical view of the problem, and it promises to simplify the computation of the molecular collisional
cross-sections.
iii) A new strategy for computing inter-molecular potential surfaces which includes the intra-molecular motion
(i.e. the motion of the nuclei in each interacting molecule). The problem here is the sampling of the
surface, which has several dimensions (≥ 4). For this, we implemented an optimized sampling, based on
the high-accuracy vibrational wavefunctions.
iv) A new strategy for computing inter-molecular potential surfaces of long rod-like molecules, like HC3N with
He or H2. In these systems, the surface is highly anysotropic and, therefore, the fitting in the angular
coordinates is particularly difficult, and this is known as “steric hindrance problem”.
v) A quasi-classical scattering code, based on a canonical Monte-Carlo strategy, to directly compute the
collisional rates (with no need to integrate the cross-sections over the Boltzman velocity distribution).
The computations briefly described above are very CPU-time consuming and require a large amount of time of
high-performance computers, like the IDRIS and CINES supercomputers. For this reason, Astromol members
46

(PV) are also involved in several high performance computing initiatives, like the development of computer grids
projects (CiGri, a project funded by the Grenoble ACI GRID, with the involvement of the institutes INRIA
and IMAG). In this context, it is worth mentioning the UJF project CIMENT (Calcul Intensif, Modelisation,
Experimentation Numerique et Technologique) co-funded by the government and the region Rhone-Alpes, whose
scope is to create and upgrade several computational platforms and associated centers of expertise.
2.5 Publications
In the last four years, the members of Astromol have published about 100 articles in international refereed
Journals. It is worth noticing that the Astromol articles account for about 15% of the total publications
reported in the last “Rapport d’activité de PCMI: Prospectives et Bilan 2001-2004”. In addition, the value of the
Astromol work is testified by the several systematic invitation to present their works in national and international
congresses. It is probably worth noticing the invitations for review talks at the four major Congresses of the
field: the IAU Astrochemistry Symposium -held in Asilomar (CA) in Aug 2005, the Protostar and Planet
VI Workshop -Kona (Hawaii) in Oct 2005, the Pacifichem Technical Workshop on Astrochemistry -Honolulu
(Hawaii) in Dec. 2005, and the Nobel Symposium on “Astrochemistry” -Stockolm (Sweden) in Jun 2006organized
by the Nobel Foundation.
2.6 Teaching and students formation
Four members of Astromol have an intense teaching activity and important administrative charges at the
University Joseph Fourier (UJF).
• Administrative charges:
– C.Kahane is the Director of the Departement Scientifique Universitaire (DSU), the structure responsible
for the re-organization of the “L1L2 de la Licence de Sciences et Technologies”;
– C.Kahane is member of CEVU and member of “la commission de finances de l’UJF”;
– J-J. Benayoun is responsible of the first year of the Master de Physique.
• Teaching: Members of Astromol teach at all levels from the first year to the Master degree.
• PhD Thesis :In the last four years three students (Sebastien Maret, Berengere Parise et Valentine Wakelam)
have been co-directed by members of Astromol and are now Post-Docs at International Institutes.
Two more students (Michael Wernli and Sandrine Bottinelli) have started their PhD thesis directed by
members of Astromol.
2.7 National and international collaborations
Astromol is involved in several major and minor projects, in collaborations with groups from France and worldwide.
These projects are briefly described in the following list:
• WAGOS: Astromol is part of the network WAGOS (Working Astronomical Group on Star formation),
between about two dozens of researchers in Grenoble (LAOG), Toulouse (CESR), Bordeaux (L3AB), and
Paris (LERMA). WAGOS has been funded by the “Project National” PCMI since its creation in 2000.
The goal of the network is the study of the solar type star formation, one of the goals of Astromol itself
(§2.1). Indeed Astromol plays a major role in this network, with several Astromol members (CC, AF,
BL, TM, PV, LW) belonging to it. The coordinator of this network is a member (CC) of Astromol. For
the next “quadriennale”, 2007-2010, we have submitted a proposal for a PPF to coordinate and fund the
activities of WAGOS.
47

• Herschel-HIFI: Astromol is involved in the scientific preparation of the heterodyne instrument HIFI, on
board the ESA satellite Herschel Space Observatory (HSO), which will be launched beginning 2008. One
of the Astromol members (CC) is the coordinator of the team “Star Formation” for the use of the HIFI
Guaranteed Time, and coordinator of the Herschel Key Program “Spectral Surveys of Star Forming
Regions”.
• FP6-THE MOLECULAR UNIVERSE is a network financed by the EC in the FP6 plan, in preparation
of the Herschel mission. The goal of the network is to provide the tools for the best interpretation
of observations of molecules in the space. This means computing the molecular data relevant for the
astrophysical observations, as well as the development of astrophysical models for their interpretation.
They are both among the goals of Astromol itself (§2.1), and, indeed Astromol plays a major role in
several milestones of the network, as well as in its management. In addition, being a training network, a
major goal is the formation of young researchers. Astromol is also a major actor in this aspect, helping
in the preparation of the 2005 Summer School “Molecular Astrophysics” and offering a post-doc position.
• ALMA: Astromol is involved in the preparation of the ALMA project, contributing to the project “Action
Specific pour ALMA” (ASA) with two of its members (CK and PV).
• Projets Nationaux: PCMI and PNPS. Astromol regularly obtains funds from PCMI since its creation,
and participate to its board (BL). It substantially contributes to the scientific results of PCMI, with about
15% of refereed articles. Lately, Astromol has also obtained PNPS funds for the study of proto-planetary
disks, in collaboration with FOST members (see §3.5).
• CNRS/NSF project “Cyanopolyynes in the interstellar space”. Since 2004 Astromol (LW, CC, BL, AF,
PV) received funds to collaborate with the University of California of Los Angeles (UCLA; M.Morris) in a
project that aims to study the formation and evolution of cyanopolyynes in several regions of our Galaxy;
from cold molecular clouds to star forming regions and regions close to the Galactic Center.
• PAI vanGogh project “Proto-planetary disks”: since 2005 Astromol (CC and BL) has been funded to
collaborate with the University of Amsterdam in a project which aims to study some key aspects of the
physics and evolution of proto-planetary disks: the ionization in the disk midplane, the evolution of the
dusty and gaseous components of the disk, and the effects of the disk irradiation from the central source.
This project involves also members of the FOST team (see also §3.5).
• JETSET : this is a EC FP6 network, described in detail in the FOST chapter.
• CIMENT is UJF project “CIMENT” (Calcul Intensif, Modélisation, Expérimentation Numérique et Technologique),
detailed in subsection “High Performance Computing” (§3.4).
In addition, Astromol members have collaborations with several colleagues world wide: P.Caselli (Arcetri
Obs., Italy), J.Cernicharo (Madrid, ES), Feigelson (Pen.State Un., USA), E.Herbst (Columbus, USA), D.Hollenbach
(Nasa Ames, USA), J.Noga (Bratislava, SK), J.Tennyson (Un.Col.London, UK), X.Tielens (Groningen, NL),
Moshe Elitzur (Univ. kentucky, USA) just to mention the most important collaborations.
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Chapter 3
Results
3.1 Overview
In this chapter we will briefly describe the activity of Astromol, enlightening the major results achieved during
the period 2002-2005. This chapter is structured into three sections. The first section describes the results
relative to the “Star Formation” activity, while the second section reports the results relative to the “Molecular
Physics” studies. A third section will describe in detail the research about the “Proto-planetary Disks”, which
is a “meeting point” of the Astromol and FOST teams. This is treated as a separate section to emphasize the
synergy between the two LAOG teams on such an important and hot field of research.
Before giving a brief description of the overall activities, we report here the three most important results
achieved by the Astromol team in the last four years. They are:
i) The study of the molecular deuteration in the regions of low mass star formation: Astromol, in collaboration
with WAGOS, had and keeps having an important role in this field of research, with the discovery of
doubly and triply deuterated molecules with D/H ratios enhanced by up to 13 orders of magnitudes with
respect to the D/H elemental abundance ratio (e.g. Parise et al. 2004). We are proud to say that our
first results on the subject, starting from 1998 (Ceccarelli et al. A&A 338, L43), have given a new élan to
this field, and triggered a flurry of new observations and new theories about the molecular deuteration in
cold and dense gas. It is important to emphasize that the new observational and theoretical framework of
molecular deuteration has lead to recognize not only the role of the grain surface and gas phase chemistry
during the pre-collapse phase, but also to identify the only way we have to probe the innermost regions of
the pre-stellar cores and the midplane of proto-planetary disks : the H2D + and HD + 2
ground transitions
in the submillimeter (Caselli et al. 2003; Ceccarelli et al. 2004). They not only give us the information
about the dynamics in those regions, but also, and not least, the measure of the gas degree of ionization,
a key quantity in both classes of objects (Ceccarelli & Dominik 2005. Our leading role in these studies
is testified by the several invitations to international congresses to review the subject (for a list of our
articles on this subject see §3.2.2).
ii) The chemical composition of the envelopes of the youngest low mass protostars, and the discovery of the
hot corinos, warm and dense regions where complex organic molecules are abundantly formed (Cazaux et
al. 2003). Astromol, in collaboration with WAGOS, had and keeps having a leading role on this field,
as testified by the several invitations to international congresses to give reviews on the subject. We were
the first to predict the existence of warm and dense regions around low mass protostars (Ceccarelli et al.
2000, A&A 357, L9), and to prove it with several observations. The most important findings is that these
regions have sizes comparable to those of our Solar System (few tens of AUs; Maret et al. 2004), and that
complex organic molecules are formed there, against the first theoretical expectations. We were also the
first to obtain the resolved images of the first discovered hot corino (around IRAS16293-2422: Bottinelli
et al. 2004b) with the PdB interferometer in two complex organic molecules.
iii) Considerable progress has been achieved in the accurate determination of intermolecular interactions with
the combination of explicitely correlated ab-initio approaches and multi-dimensional investigations. In
49

particular, we calculated a 9D H2O-H2 potential energy surface of unprecedented accuracy and complexity
(Faure et al 2005a). The associated quenching rate for vibrationally excited water has been calculated
using a classical Monte Carlo canonical approach which corrects by more than one order of magnitude
the existing estimations (Faure et al 2005b). These results will lead to a thorough re-interpretation of
vibrationally excited water emission spectra from space.
iv) We have also reconsidered the role of electrons in the collisional excitation of molecules in harsh environments
(PDR’s, planetary nebulae, etc) in collab. with the group of J. Tennyson at UCL. Rotational
transitions with ∆J > 1, which are neglected in pure dipolar approximations, were found to have rate
constants similar or even larger than those with ∆J = 1. Results of astrophysical relevance have been
obtained for H + 2 , CO+ , NO + , HCO + , H + 3 , H3O + , and asymmetric-top isotopologs of water H2O, HDO
and D2O (Faure et al. 2004 and references therein).
3.2 Star Formation
3.2.1 Overview
Astromol members carry out observational and theoretical studies of the star formation process. These cover
low to high mass (§3.2.5) stars, and concern the very first stages represented by the Molecular Clouds and
Pre-Collapse phases to the last phases before the so called Pre-Main-Sequence (PMS) phase, which is a target
of the FOST team research. Specifically, Astromol studies focus on:
• Molecular Clouds, as the nurseries of newly forming stars (§3.2.2, 3.2.6);
• Pre-Stellar Cores, the condensations just before the collapse sets in ((§3.2.2);
• Class 0 sources, believed to be the youngest known protostars (§3.2.2, 3.2.3, 3.2.6, 3.2.7);
• Class I sources, believed to represent the transition between Class 0 sources and PMS objects (§3.2.2,
3.2.3, 3.2.6, 3.2.7);
• Proto-planetary disks (this part is described in §3.5)
• Molecular outflows, the result of the interaction of the material ejected during the Class 0 and Class I
phases with the surrounding Molecular Clouds (§3.2.4).
To study the formation of the stars and how this influences the surroundings, Astromol members use observational
facilities which span the X-ray (§3.2.6) to radio frequency range. In addition, although molecular
spectroscopy is the Astromol privileged tool to study star forming regions, also dust continuum emission and
features (§3.2.7) have been used by the Astromol members. Consequently, a wide range of models is developed
to interpret such a wide range of observations. The following sections give a brief summary of the Astromol
research in the mentioned fields.
3.2.2 The deuteration in the first phases of star formation
Molecular deuteration was considered sort of a solved problem in Astrophysics, until the first detections of
multiply deuterated molecules in low mass star forming regions, which showed molecular D/H ratios enhanced
by up to 8 orders of magnitude with respect to the elemental D/H ratio (Ceccarelli et al. 1998 A&A 338, L43;
2001 A&A 372, 998; 2002 A&A 381, L17; Loinard et al. 2000 A&A 359, 1169; 2001 ApJ 552, L173). The
current models were unable to fully explain those observations (e.g. Roberts & Millar 2002, A&A 361, 388).
Astromol observational work in the 2002-2005 period has helped to solve the problem, which now is much better
mastered. Specifically, the following aspects were elucidated:
• The extreme deuteration observed in low mass protostars sets on during the pre-collapse phase, when the
matter is very dense (≥ 10 6 cm −3 ) and cold (≤ 10 K). This is in the so called Pre-Stellar-Core phase. A
key factor which makes the deuteration so extreme is the CO freeze-out onto the grain mantles (Bacmann
50

et al. 2002, 2003). When CO disappears from the gas phase (because condensed onto the grain mantles),
ratio is highly enhanced and can reach the unity (Caselli et al. 2003). Besides, even the
the H2D + /H + 3
multiple deuterated forms of H + 3 , namely HD+ 2 and D+ 3 , can become more abundant than H+ 3 (Roberts,
Herbst & Millar 2003, ApJ 591, L41). Since the deuterated forms of H + 3 react with all molecules in the
gas phase exchanging the D atom, they transmit the deuteration to molecules (e.g. Roberts, Herbst &
Millar 2004, A&A 424, 905).
• Molecules like H2CO, CH3OH and H2S, which are thought to form on the grain surfaces rather than in
the gas phase, have been found to show up the largest multiple deuteration factors (Parise et al. 2002,
2004a; Vastel et al. 2003). Very likely this is because they are formed by hydrogenation of CO (and S)
during the last phases of the pre-collapse, when the CO depletion is larger (this is a definition!).
• Water though does not follow the same route. Indeed, the gaseous HDO/H2O ratio is less than 3% in low
mass protostars (Parise et al. 2005), whereas HDCO/H2CO and CH2DOH/CH3OH ratios are around
30%. Even the solid HDO/H2O ratio is indeed less than 3% (Parise et al. 2004b), which confirms the
lower deuteration of water. One possible interpretation is that water forms on the grain surfaces at an
higher temperature, because the H2O condensation occurs already at about 100 K. This would limit the
H2D + /H + 3 ratio.
• At the center of the Pre-Stellar Cores, all CO is now believed to almost completely freeze-out onto the
grain mantles. Therefore, CO and all the other heavy-bearing molecules disappear from the gas phase,
and the best tool to probe those regions is the H2D + emission (Caselli et al. 2003). The study of the
profile of the H2D + ground state transition provides a valuable tool to probe the velocity field at the
center of the condensation, and, consequently, whether and how the collapse sets in (van der Tak, Caselli
& Ceccarelli 2005).
• Similarly to the centers of the Pre-Stellar Cores, the gas in the midplane of the proto-planetary disks
surrounding solar type protostars can only be probed by the H2D + emission (Ceccarelli et al. 2004,
Ceccarelli & Dominik 2005). This aspect will be discussed in more detail in §3.5.
3.2.3 The hot corinos of solar type protostars
In the first phases of the star birth, the future star is embedded in and totally obscured by the infalling material,
which forms a thick envelope. The density in the envelope ranges between 10 4 to 10 8 cm −3 , and the temperature
ranges between 10 and about 200 K. The exact density and temperature structure depends on the dynamics of
the collapse. It is therefore extreme important to study the density and temperature profiles of these envelopes
and how they evolve with time. Furthermore, giving the involved densities and temperatures, protostellar
envelopes are privileged sites for a rich chemistry to occur. The chemical composition of these envelopes is
not only interesting in itself. The matter in protostellar envelopes forms the proto-planetary disks, which will
eventually form the planets and comets. During the comets bombarding phase, molecules formed during the
protostellar collapse phase may be preserved ( for example frozen-out onto the dust grains) and brought to
the formed planets. It is therefore of paramount importance to know the molecular complexity reached in the
protostellar envelopes. In this context, Astromol members, in collaboration with WAGOS, have contributed to
three major aspects:
• The study of the physical structure. Astromol members published the very first articles reconstructing
the density and temperature profiles of protostellar envelopes ( Ceccarelli et al. 2000 A&A 355, 1129;
2000 A&A 357, L9; 2001 A&A 372, 998; Maret et al. 2002, 2004, 2005). Based on these studies, the
protostellar envelopes have approximatively the structure of free-infalling envelopes, as predicted by the
inside-out theory by Shu and colleagues. In addition, they possess warm and dense regions close to the
central object where the icy grain mantles sublimate, injecting into the gas phase the molecules formed
and/or trapped into the mantles.
• The study of the chemical composition. Chemically, the protostellar envelopes are formed by two components:
i) an outer envelope (defined by where the dust temperature is less than ∼ 100 K), whose chemical
composition is similar to that in molecular clouds; ii) an inner envelope, where the chemistry is dominated
by the material sublimated from the icy grain mantles. In this inner envelopes, large quantities of H2O,
H2CO, CH3OH, SO and SO2 molecules are found (Maret et al. 2002, 2004, 2005; Wakelam et al. 2004a,
2004b).
51

• The hot corinos. More spectacular, abundant complex organic molecules in the inner envelopes have been
discovered by Astromol (Ceccarelli et al. 2000, A&A 362, 1122; Cazaux et al. 2003; Bottinelli et al.
2004b). Following these reports, a (short living) debate about the nature of these hot corinos arose, which
was settled by the first images of hot corinos. These images (obtained with PdB -Bottinelli et al. 2004band
SMA -Kuan et al. 2004 ApJ 616, L27) show that indeed complex molecules are formed in very small
regions ( ∼ < 100 AU) close to the central object, as predicted by the previous Astromol studies (see Fig.
3.1).
The importance of the contribution of the Astromol studies in this field are testified by the invitation to give
review talks in the major 2005 (just to mention the most recent ones) congresses of the field: the IAU 231
Symposium on “Astrochemistry”, the Symposium “Protostars and Planets V”, and the Nobel Symposium 133
“Cosmic Chemistry”
Figure 3.1: The 1.3mm continuum (upper panel) image of the solar type protostar IRAS16293-2422, which is
formed by a proto-binary system. The lower panel reports the same field as seen in one line of the methyl
format (CH3OHCO). The North source is the brightest in the continuum, which implies that it is surrounded
by an envelope more massive than the South source. On the contrary, the South source shines in the molecular
emission, whereas the North source is barely detected. Very likely this corresponds to a different chemical
composition of the two sources. The South source clearly possesses a “hot corino” about 300 AU in diameter,
whereas the hot corino of the North source is smaller and/or less rich in molecules (from Bottinelli et al. 2004b).
52

3.2.4 The outflows of protostars
Astromol members have studied for several years the physics and chemistry of protostellar outflows, which are
one of the most spectacular mass-loss phenomenon that takes place all along the protostellar phase. The current
picture is that these outflows results from the acceleration and the sweeping up of ambient material by a faster,
strongly collimated jet from the protostar. The main issues addressed by Astromol are the nature of the shock
acceleration mechanism of the molecular gas, in particular the type of shock, either purely hydrodynamical (J-)
or magnetohydrodynamical (C-), the relation the flow holds to the high-velocity atomic/ionized (Herbig-Haro)
jet, and the impact of outflows on the parental cloud, both dynamically and chemically.
Until now, most of the information on outflows has been derived from observations probing the cold (20-
50 K), post-shocked molecular material. However, the bulk of mass of the shocked molecular gas lies at much
higher temperatures, in the range 100-2000 K, which can be probed by high-excitation molecular lines in the
mm/submm domain. The data analysis relies strongly on comparison with shock diagnostics, for which we use
state of the art models developed by Pineau des Forets and S. Cabrit in LERMA (Paris).
The confirmation that (MHD) C-shocks play a major role in the dynamics of outflows has been provided
by ISO. The observation of pure H2 rotational lines with ISOCAM/CVF in the archetypal HH 1/2 system in
Orion (Lefloch et al. 2003) has revealed large column densities of warm gas with excitation temperature Tex=
500-1300 K, substantially cooler than the previously known component probed by the near-IR ro-vibrational
H2 lines. Comparison with state of the art grid models (Cabrit et al. 2004) shows that the warm H2 column
density greatly exceeds that predicted for purely hydrodynamical (J-type) shocks, and allows to constrain the
magnetic field. In the leading edge of the jet, where the geometry of the emission allows a simple modeling,
the emission could be satisfyingly reproduced by MHD shock models with neutral-ion decoupling. This result
appears quite general and is one of the most convincing evidences for C-shocks in outflows.
The determination of the physical conditions in the pre-shock and the shocked gas (density, ortho-para ratio)
requires the observations of additional molecular tracers. The molecules formed from the material released from
dust grain mantles in the gas phase through shattering or sputtering in shocks are privileged tools for such study.
SiO has long been recognized as a school case (Schilke et al. 1997 A&A 321, 293; Lefloch et al. 1998 ApJ 504,
L109). The S-bearing species are also of particular interest as their chemistry is relatively fast (τ ∼ 10 4 yr). We
have carried out several observational studies (Wakelam et al. 2004, 2005), which have required the development
of a time-dependent chemical model with up-to-date reaction rate coefficients. We could show that S-bearing
molecular ratios cannot be easily used as chemical clocks, contrary to a suggestion made a few years ago by
various authors, but it allows to constrain the depleted form of sulphur onto grains (Wakelam et al. 2005).
It has long been proposed that the X-ray/UV radiation produced in strong protostellar shocks could affect
the chemical composition of gas and dust in the quiescent surroundings, and the region downstream of HH 2 (see
above) was considered as an illustrative case of such processes. A detailed study based on ISOCAM observations
and the millimeter SO line emission showed however that the gas downstream of HH 2 was not as quiescent
as claimed so far, and that the “anomalous” chemical gas composition was probably the result of previous
protostellar ejections (Lefloch et al. 2005).
3.2.5 The intermediate/high mass protostars
A large number of observations indicate that HII regions play an important role in spreading star formation
throughout the Galaxy. Most of the embedded young stellar clusters in the solar neighborhood are adjacent
to HII regions excited by more evolved stars, like Orion or Perseus OB2, to name but a few. It is estimated
that 10%-30% of stars in mass in the Galaxy are formed under the influence of adjacent HII regions. Various
scenarios of triggered star formation in the molecular layer surrounding the HII regions have been proposed
(Elmegreen & Lada 1977 ApJ 214, 725; Whitworth et al. 1994 MNRAS 268, 291; Fukuda & Hanawa 2000 ApJ
533, 911) but detailed comparison with the observations, especially at early ages, is still missing. Two lines of
investigation have been followed.
i) In collaboration with J. Cernicharo (DAMIR, Madrid), we have started a systematic multi-wavelength
study of the Trifid nebula (M20), from centimeter to near-IR wavelengths, which benefited the advent of ISO,
allowing to study the properties of the Photon-Dominated Region at the interface between the nebula and
the molecular cloud. A comprehensive picture of this young HII region (∼ 0.3 Myr) could be obtained, from
53

the massive deeply embedded protostellar cores and the bright rimmed globules detected in the compressed
surrounding cloud, to the “naked” cores and the protoplanetary disks exposed to the ionizing radiation in
the nebula (Cernicharo et al. 1998; Lefloch & Cernicharo 2000, Lefloch et al. 2001, 2002). Recent Spitzer
observations have unveiled the young stellar population of M20 and the protostellar cluster forming in the
massive cores (see Fig. 3.2; Rho et al. 2005).
ii) In collaboration avec L. Deharveng, A. Zavagno (Marseille), A. Whitworth (Cardiff), we have undertaken
a multi-wavelength survey for evidences of induced star formation around young HII regions, to study the
molecular emission of the parental cloud and compare the properties of the protostellar condensations and the
young stellar clusters with the predictions of the scenarios of triggered star formation (see e.g. Deharveng et al.
2004).
Figure 3.2: Images of the Trifid Nebula in the visible (left panel) and in the Infrared (right panels). The IR
images have been obtained by SPITZER Rho et al. 2005 and show the presence of many young stars invisible
in the optical, because obscured by the thick dusty molecular cloud.
3.2.6 The X-rays from young protostars
• X-ray irradiation of circumstellar disks
X-ray emission is ubiquitous among young stars (see Feigelson & Montmerle 1999, ARAA, 37, 363). In
low-mass stars, the main X-ray emission mechanism is due to solar-type magnetic activity, which manifests
itself mainly in the form of hour-long flares. The average X-ray luminosity (normalized to the stellar bolometric
luminosity) is very high (LX/Lbol ∼ 10 −4 − 10 −3 ), i.e., three to four times higher than for the present-day Sun.
In the case of young stars, the prime target for the X-rays is the circumstellar disk. The main effect is ionization
(induced by the photoelectric effect): although the results depend to some extent on the density-radius relation,
in most cases the disk is ionized throughout its extent, with representative values of the ionization fraction
comparable to the average ISM (xe ≈ 10 −7 ) (Glassgold, Feigelson, & Montmerle 2000, Protostars & Planets IV,
University of Arizona Press, p.429). The fact that the circumstellar disk is ionized (albeit weakly) is important
because it provides a coupling between the disk material and magnetic fields, especially in the inner parts of
the disk, close to the “accretion-ejection” engine. Note however that the densest parts of the disk, along the
equatorial plane, may be too thick for X-rays to penetrate them, resulting in an embedded “dead zone”. It is
possible that such a dead zone, being neutral, be favorable to the formation of planets (see also the discussion
in §3.5.
Another effect is that of X-ray heating. Glassgold et al. (2005) have shown that this heating is efficient in the
outer, tenuous layers of the disk, resulting in an extended (several tens of AU) warm photosphere (T ∼ 3, 000 K),
explaining the observed CO overtone IR lines. As a result, the vertical temperature structure of circumstellar
disks must be “inverted”, i.e., cold along the horizontal plane and warm at high altitudes.
54

Since X-rays mainly come from flares, as in the case of the Sun, one must also consider the effect of energetic
particles hitting the disk. In particular, energetic protons and α nuclei generate nuclear spallation reactions on
the gas, the resulting particles being subsequently trapped in macroscopic bodies like meteorites. This “internal
irradation” scenario has successfully explained almost all the “extinct radioactivities” in solar system meteorites
(Gounelle et al. 2001, ApJ, 548, 1051; Montmerle 2002, Feigelson et al. 2005).
Taking a broader perspective, the irradiation phenomena that must have taken place during the very young
stages of circumstellar disks around solar-type stars may set interesting boundary conditions for the origin of
life (Montmerle 2005).
• X-ray irradiation of molecular clouds
After nearly three decades of theoretical work and expectations, diffuse X-ray emission has been discovered
massive star-forming regions (M17 : Townsley et al. 2004). This region is excited by about a dozen of O3
stars (the most massive stars in the Galaxy). The diffuse X-ray emission was predicted as coming from a large
hot bubble (T ∼ 10 7 K) of low-density gas, inflated by the intense and fast stellar winds from these stars.
With stellar mass-loss rates reaching ˙ M ∼ 10 −5 M⊙/yr and velocities vw ∼ 4, 000 km s −1 , bubbles several pc
in size or more were expected. It took the sharp, subarcsec resolution of Chandra to distinguish truly diffuse
X-ray emission from the unresolved X-ray emission of the thousands of low-mass stars present in such massive
star-forming regions (Fig. 3.3).
Figure 3.3: ISO pointings of M17, from the O star cluster into the molecular cloud, superimposed on the
Chandra image. Square: ISOCAM field of view; Sn: SWS pointings; Ln: LWS pointings (dashed ellipse: fields
in the direction of the molecular cloud). Thin, closely spaced isophotes: 330 MHz emission; loose isophotes:
IRAS 100 µm emission.
With an intense diffuse X-ray flux, spread over a large volume, it was important to search for large-scale Xray
irradiation effects on the parent giant molecular cloud of M17. Several possible tracers, observed at different
wavelengths, from the radio cm range to the mid-IR range (ISO spectroscopy), were examined from archival
data (Montmerle & Vuong 2005). The results were however inconclusive (like extended excess C + emission),
because of the presence, simultaneous with X-rays, of UV photons from the massive stars, able to travel to large
distances in the tenuous, external layers of the molecular cloud. New, targeted observations in the mm range,
are planned to probe the dense parts of the molecular cloud, which only X-rays can penetrate.
• X-ray absorption and metallicity of molecular clouds
While X-rays are emitted by the young stars born in a molecular cloud, they are absorbed by the surrounding
material, as explained above. Then one can take advantage of this absorption to map the column density NH,X
towards each star, by fitting the observed X-ray spectrum. X-rays are absorbed by heavy atoms, whatever the
material (gas or grains) in which they are located. 1-10 keV X-rays can penetrate up to the equivalent of several
55

tens of visual magnitudes, hence probe deeply into the densest regions of molecular clouds. When correlated
with the IR extinction in front of the same stars, which depends essentially on the dust grain size distribution,
one has in principle (with sufficient IR data) a powerful tool to measure the metallicity of molecular clouds.
This was done successfully by Vuong et al. (2003) for the nearby ρ Oph cloud (up to AV ∼ 50), resulting
in a solar cloud metallicity (Z ∼ Z⊙). Other clouds were also studied, but the available data do not probe
sufficiently dense regions to establish a good NH,X vs. AV correlation.
3.2.7 Dust around protostars
The continuum emission (spectral and spatial distributions) from the dust in the protostellar envelopes gives
important information on the structure of the envelope. The study of the dust continuum is in fact a technique
used by several groups in the world. It is complementary to that exposed in §3.2.3, which uses the rotational
transitions of molecules. Astromol has used both techniques wherever the opportunity presented (Maret et
al. 2004). However, Astromol research on the dust continuum has been more original in the analysis of the
dust features in the Far Infrared, and specifically in the range (45-200 µm) observed by the Long Wavelength
Spectrometer (LWS) on board ISO. This range of wavelengths was thought to not contain any interesting
dust feature. However, Astromol has revealed that an important feature is observed between 90 and 100 µm
(Ceccarelli et al. 2002b). A systematic study of the LWS spectra of low to intermediate protostars has found
that more than 50% of the protostars show up this feature (Chiavassa et al. 2005). The nature of the carrier of
the observed feature is not totally sure. At present, the most reasonable hypothesis is that calcite is responsible
for it. In support of this interpretation, very recently calcite has been revealed in the comet Temple 1 (Deep
Impact mission; Lisse et al. 2005, IAU Circular 8571). This is an important observation, because it shows a
clear link between the comets and the proto-stellar phase. Furthermore, and mostly important, the presence of
calcite in protostars and comets rises the question of its formation. On Earth and in the Solar System objects
(meteorites), calcite is formed by aqueous alteration. However, both in protostars and comets, evidently, no
liquid water is present. We have proposed that the interaction of the X-rays emitted from the central object
(§3.2.6) with the dusty envelope, could be at the origin of the calcite formation (Ceccarelli et al. 2002b). The
interest in this discover is that, if the calcite interpretation is confirmed, this may have some far reaching
consequences because the same mechanism forming calcite may be also form pre-biotic molecules.
3.3 Molecular Physics
3.3.1 Overview
The near-future large scale observatories HERSCHEL and ALMA will open up the Universe to high spatial and
spectral resolution studies of molecules. These new missions will make a major breakthrough in our knowledge of
the key astrochemical processes involved in the origin and evolution of planets, stars, and galaxies. HERSCHEL
and ALMA will lead to a multitude of molecular line data in a great variety of astrophysical environments.
Identification, analysis and interpretation of this data in terms of the physical and chemical characteristics of
the astronomical sources will require a concerted effort by physicists, chemists and astronomers in the areas of
molecular spectroscopy, collisional excitation processes, chemical reactions, and astronomical modeling.
In this ambitious context, our objective since 2002 is to focus our theoretical activity on the calculation
and renewal of potential energy surfaces (PES) and collisional data for astrophysics. Several recent studies
have shown that inaccuracies in the PES are indeed the largest source of error in collisional rate calculations.
Furthermore, the standard quantum close-coupling method used to compute these rates is computationally
efficient at low temperatures only. The development of reliable approximate quantum treatments or methods
based on classical mechanics are thus highly desirable. The specific objectives of our theoretical work are
therefore:
• Calculations of PES at the highest level of accuracy by employing state-of-the-art ab initio methods.
• Calculations of collisional rate constants by employing both full dimensional quantum calculations and
practical quantum/classical approximations.
56

• Monitoring of the error propagation from the PES to the collisional rates, and subsequent monitoring of
the collisional approximations, with first results for inelastic rotational rates involving CO, HC3N, (also
H2O and NH3 in collab. with M.L. Dubernet and E. Roueff), and for H2O quenching.Corresponding tools
will be included in the BASECOL database.
Furthermore, the dependence of astronomical modeling to the accuracy of collisional rates is also a very
challenging issue which our group has started to address.
3.3.2 Potential energy surfaces
Within the Born-Oppenheimer approximation, inelastic cross sections and rate constants are obtained by solving
for the motion of the nuclei on an “electronic” PES, which is independent of the masses of the nuclei. Recent
studies have demonstrated that computational techniques employing advanced treatments for both electronic
and nuclear motion problems have the ability to rival the accuracy of experimental data. These studies all
employed convergent hierarchies of basis sets and correlation methods to solve the electronic structure problem.
The CCSD(T)-R12 method
In contrast to conventional calculations, correlated methods that include explicitly the inter-electronic coordinates
into the wave function can describe properly the electron-electron correlation cusp and offer a direct way
of reaching the basis set limit values within a single calculation, i.e. without extrapolation. Among various
explicitly correlated methods, the R12 coupled cluster theory with singles, doubles and perturbative triples
(CCSD(T)-R12) (Noga & Kutzelnigg 1994 J. Chem. Phys., 101, 7738) is computationally practical and proved
highly accurate (Ramajäki et al. 2004 Mol. Phys, 102 2297), in particular using adequate R12-suited basis
sets (Kedˇzuch et al. 2005 Mol. Phys., 103, 999). Generalizing the idea of Kutzelnigg (Kutzelnigg 1985 Theor.
Chim. Acta, 68, 445), in CCSD(T)-R12 one takes care of the correlation cusp by inclusion of linear terms in
the inter-electronic coordinates into the exponential wave function expansion.
Our corresponding production code DIRCCR12 1 implements an original trick to accelerate the calculations
of CCSD triples and is efficiently parallelized up to 6-8 processors. It provides auto-adaptative algorithms to
handle load imbalance, heterogeneous processors and distributed scratch disks on clusters. It achieves a typical
parallel performance over 500 Mflops per processor on the IBM Power4 Regatta supercomputer at IDRIS with
minimal I/O bottlenecks. This code is routinely used either for conventional CCSD(T) calculations or for
explicitely correlated CCSD(T)-R12 using our specifically developed R12-suited basis sets for H to Ne.
H2O – H2
We have constructed a full nine-dimensional interaction potential for H2O – H2 calibrated using high-accuracy,
explicitly correlated wave functions. All degrees of freedom are included using a systematic procedure transferable
to other small molecules astrophysically or atmospherically relevant. CCSD(T)-R12 5D calibration
calculations were run on the IDRIS and CINES national computers, while the Monte Carlo sampling of the
9D hypersurface was the first dimensioning application of the Grenoble computer grid (CiGri), developed with
support from the ACI Grid. The resulting 9D hypersurface contains in particular all relevant information to
describe the interaction of H2 with all H2O isotopomers in zero point or excited bending states.
As a first application, we estimated rate constants for the vibrational relaxation of the ν2 bending mode of
H2 O obtained from quasiclassical trajectory calculations in the temperature range of 500 – 4000 K. Our hightemperature
(T > 1500 K) results are found compatible with the single experimental value at 295 K. Our
rates are also significantly larger than those currently used in the astrophysical literature and will lead to a
thorough reinterpretation of vibrationally excited water emission spectra from space (see Faure et al JCP 2005
122, 221102).
In a second paper (Faure et al, JCP 2005 123 104309) we emphasized the role of rotation in the vibrational
relaxation of water. As a further conclusion of this quasiclassical analysis, we also predict that the popular
1 see the repository http://www-laog.obs.ujf-grenoble.fr/∼valiron/ccr12/index.html for details on the code and for related bib-
liography
57

quantum VCC-IOS approximation may fail to properly describe the H2 O quenching. This stresses the need
to develop more advanced approximation schemes to describe the ro-vibrational collisional processes involving
molecules with large ∆J splittings such as water, ammonia, etc...
HC3N – H2
The “steric hindrance” problem solved, first quantum inelastic rates obtained.
Two new PES have been calculated at a CCSD(T) level for the HC3N–He and HC3N–H2 systems by P. Valiron.
The new HC3N–He agrees pretty well with the PES obtained by Akin-Ojo et al 2003. Pionnering CCSD(T)-R12
calculations with 920 basis set orbitals and 10 occupied (with frozen core) permitted to assess the accuracy of
this PES. Steric hindrance problems involving the HC3N rod limit the convergence of the angular expansion
of the PES, as anticipated by Green & Chapman (1978 ApJS 37, 169). However for the low energy regime
M. Wernli showned it is feasible to regularize the PES by smoothing out the repulsive walls and to achieve a
perfectly converged angular expansion.
Corresponding close-coupling calculations led to surprising results due to the rod-like features of the PES. Firstly
quantum interferences strongly defavour odd ∆j transitions and favour even ∆j ones. This propensity rule is
likely to favour the J=1 population for H2 densities in the 10 3 –10 4 cm −3 range. Secondly, despite the very large
HC3N dipole moment, the para-H2 and ortho-H2 rates are nearly identical. While the even ∆j propensity rule
could not be found in the quasiclassical calculations by Green & Chapman (1978 ApJS 37, 169), the new rates
remain within the same order of magnitude despite the very crude an electron gas model PES. This is not too
surprising as the rod-like features of the PES dominate the scattering.
3.3.3 Energy transfer processes
Energy exchange processes between molecules, atoms and particles are responsible for thermal balance and line
formation in a great variety of astronomical environments. Molecular line emissions are generally produced in
low-temperature (T < 1000 K) and low-density (n < 10 10 cm 3 s −1 ) conditions far from thermodynamic equilibrium
and through a complex competition between radiative and collisional processes. A detailed knowledge of
rate constants for all microscopic processes that drive the populations of the emitting levels is thus necessary
to interpret the observed spectra. Despite some recent progress in laboratory measurements of state-to-state
collision rates, astrophysical models still rely heavily on theoretical predictions owing to the vast network of
relevant states which span a wide range of excitation energies. During the past four years, our group have made
significant advances in the understanding of molecule-molecule and electron-molecule collisions.
Molecule-molecule collisions
In standard molecular environments such as dense interstellar clouds or star-forming regions (T < 300 K,
n > 10 4 cm 3 s −1 ), hydrogen molecules H2 are the dominant exciting species. We have recently revisited the
collisional excitation of three astronomically very important molecules: CO, H2O and HC3N in collisions with
H2. As described previously, the H2O−H2 and HC3N−H2 PES have been computed by our group using high
accuracy ab initio methods. For CO-H2, we employed a very recent PES obtained by Jankowski and Szalewicz
(2005). The accuracy of these three PES is similar and lies within a few cm −1 in the relevant regions of the
PES. Such a precision is necessary at low temperatures (T < 50 K) to guarantee that inaccuracies in the PES
represent only a small fraction of collision energies. Our main results for the above mentioned systems are
summarized below:
• Rotational excitation of CO by para- and ortho-H2
Quantum close-coupling calculations were performed for rotational levels of CO up to 5 and temperatures
in the range 5−70 K (Wernli et al 2005). Our results were compared with those obtained by Flower
(2001) on a previous, less accurate, PES. The new rigid-rotor CO−H2 PES of Jankowski and Szalewicz
(2005) was thus shown to strongly affect the resonance structure of the rotational cross sections at very
low collision energies (E < 60 cm −1 ). As a result, the calculated rates at 10 K were found to differ by up
to 50% with those obtained by Flower (2001). Conversely, at temperatures larger than about 70 K, the
effect of the new PES was found to be only minor.
58

Rate coefficient (cm 3 s -1 )
1e-10
1e-11
1e-12
−
−
1e-13
0 1000 2000 3000 4000
Temperature (K)
Figure 3.4: Rate constant (in cm 3 s −1 ) as a function of temperature for the vibrational relaxation of H2O(v2 =
1 → 0) by H2. QCT results are plotted as filled circles for T ≥ 1500 K (with error bars corresponding to 2 Monte-
Carlo standard deviations) and as arrows (lower limits) for T < 1500 K. The dotted curve denotes empirical
rates reported by (González-Alfonso et al. 2002 A&A, 386, 1074). The empty circle gives the experimental
value of (Zittel & Masturzo 1991 J. Chem. Phys., 95, 8005) at 295 K. The solid line corresponds to a standard
interpolation of the high temperature (T ≥ 1500 K) QCT results. Taken from Faure et al. (2005).
• Vibrational relaxation of H2O(v2 = 1) by H2
Classical calculations were carried out using our nine-dimensional H2O−H2 PES where only the bending
mode of water (first excited state at 1595 cm −1 above the ground state) was considered, i.e. all stretching
modes were neglected. The quasi-classical trajectory (QCT) method was employed as an alternative to
computationally impractical full close-coupling calculations. Our results, as presented in Fig. 3.4, have
shown that the rate constant for vibrational relaxation is one to two orders of magnitude greater than the
empirical prediction used by astrophysicists. Our high-temperature results (T > 1500 K) were also found
compatible with the single experimental point at 295 K. Moreover, we observed a significant rotational
enhancement of the vibrational rates, suggesting that standard quantum approximations (e.g. VCC-IOS)
might fail for molecule-molecule collision pairs with large rotational constants (Faure et al. 20005b).
• Rotational excitation of HC3N by para- and ortho-H2
Quantum close-coupling and classical calculations have been carried out at low temperatures (T < 50 K).
Our major result, as illustrated in Fig. 3.5, is the presence of strong quantum interferences in the rotational
rates. These interferences, which simply reflect the strong even anisotropy of the PES, are obviously absent
in our classical results and those of Green & Chapman for HC3N−He (1978). The ∆J = 2 propensity
rule was also shown to strengthen the inversion of the J = 1 rotational level of HC3N for H2 densities in
the range 10 3 -10 5 cm −3 , thus giving new insights to the HC3N astronomical masers. Another important
result is the complete absence of a para/ortho-H2 selectivity. This last result again reflects the particular,
non-multipolar, anisotropy of the PES.
• Methodological developments
The previous results have required original developments in the framework of quasi/semi-classical and
transition-state theories. In line with theories proposed a few years ago by Wiggins, Wiesenfeld and
colleagues (Wiesenfeld 2004; Wiesenfeld 2005), we have thus extended and generalized the concept of
transition states, widely used in the understanding of chemical reactivity, to rotationally inelastic collisions
(Wiesenfeld, Faure & Johann 2003). We have also reconsidered the semi-classical quantization of the rigid
asymmetric rotor (such as H2O) and we have shown that standard classical trajectories cannot be employed
to compute state-to-state cross sections in this case, owing to ambiguities in the assignment of the semiclassical
action to a particular quantum states (Faure & Wiesenfeld 2004). As a result, collisions involving
asymmetric top species does require a quantum treatment of rotation.
59

Rate constant (cm 3 s -1 )
1e-09
1e-10
1e-11
1e-12
1e-13
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
Final J of HC N 3
Figure 3.5: Rate constant (in cm 3 s −1 ) at 40 K for the rotational excitation of HC3N(J = 0) by para-H2 as
a function of the final J. Our QCT results are plotted as grey open circles (with error bars corresponding to
2 Monte-Carlo standard deviations). The black solid curve denotes quantum close-coupling calculations. The
black dashed curve gives the classical results of Green & Chapman (1978 ApJS 37, 169) for He. Taken from
Wernli et al. (2005).
Electron-molecule collisions
The fractional ionization or electron fraction ne is typically of the order of 10 −6 −10 −3 in photon-dominated
regions or cometary comae and much smaller in dense dark clouds. Electrons may however become efficient
exciting species owing to their strong electrostatic interactions with molecules. Indeed, rate constants for
electron-impact excitation of molecules are typically five orders of magnitude greater than the corresponding
ones for excitation by the dominant neutral species (H and H2). Electrons are thus the dominant collision
partners as soon as ne > 10 −5 .
In collaboration with the group of University College London headed by Jonathan Tennyson, we have recently
reconsidered the role of electrons in the excitation of molecules by employing the UK molecular R-matrix
approach. Briefly, the R-matrix theory is based on a high accuracy ab initio description, inside a sphere, of the
electron-molecule interaction (see Gorfinkiel et al. (2005) and references therein). We have shown that simple
long-range approximations, widely used in the astrophysical literature, are not reliable for computing rotational
or vibrational rates. In particular, rotational transitions with ∆J > 1, which are neglected in pure dipolar
approximations, were found to have rate constants similar or even larger than those with ∆J = 1. As electron
temperatures up to several thousands of Kelvin are needed, the adiabatic-nuclei-rotation approximation was
employed in our calculations (Faure & Tennyson 2002). We have considered recently the following astronomical
important species: the linear molecular ions H + 2 , CO+ , NO + and HCO + (Faure & Tennyson 2001 MNRAS
325, 443); the symmetric-top molecular ions H + 3 and H3O + (Faure & Tennyson 2003); and the asymmetrictop
isotopologs of water H2O, HDO and D2O (Faure et al. 2004a). Collisions of electrons with H2O are
particularly interesting because these have been studied extensively experimentally. Figure 3.6 compares our
results at 6 eV with the rotational excitation measurements of (Jung et al. 1982 J. Phys. B, 15 3535) and the
elastic measurements of (Cho et al. 2004 J. Phys. B, 37 4639). We can notice the very good agreement with
the elastic measurements of Cho et al. (2004) over the whole measured angular range. The agreement with
the data of Jung et al. (1982) is also quite satisfactory (within 50%) in view of the experimental uncertainties.
A good agreement between our calculations and the very low energy storage-ring measurements of Field and
co-workers (in preparation) was also observed very recently, suggesting again that R-matrix calculations give
an accuracy rivalling, and sometimes exceeding measurements (Faure et al. 20004b).
60

Differential Cross Section (Å 2 sr -1 )
6
5
4
3
2
1
0
0 20 40 60 80 100 120 140 160 180
Scattering Angle (deg)
Figure 3.6: Computed and measured DCS of water at 6 eV. The present elastic (rotationally summed) DCS
is given by the thick solid line. Other lines denote partial state-to-state DCS (dashed line: 0 → 1; solid line:
0 → 0). The filled squares correspond to the experimental elastic DCS of (Cho et al. 2004 J. Phys. B, 37
4639). The open circles and diamonds correspond respectively to the experimental pure elastic (∆j = 0) and
rotationally inelastic (∆j = ±1) DCS of (Jung et al. 1982 J. Phys. B, 15 3535); the sum of both contributions
is given by the stars. Taken from Gorfinkiel et al. (2005 Eur. Phys. J. D, 35, 231).
3.4 High Performance Computing
The Astromol team has been involved in several high performance computing initiatives to achieve its objectives.
The most demanding issue was the construction of multi-dimensional ab-initio potential energy surfaces and their
calibration to cm −1 accuracy using our explicitely correlated coupled cluster approach. The inelastic scattering
calculations proved also very demanding, both at the classical level (to investigate the H2O quenching) and at
the close coupling level (CO colliding with H2 and HC3N colliding with He and H2). In the future, exploration
of multi-parametric models of astrophysical sources may also prove very demanding, as was already explored
by S. Maret.
In order to achieve our goals at optimal cost, we combined a hierarchy of approaches and machines.
• Our development benefited of a few dedicated PCs acquired with support of PCMI and CNES, and
complemented at the end of 2004 by a 64-bit opteron biprocessor with 8 GB memory which was devoted
to explicitely correlated investigations. This latter machine was also used as a testbed for the preparation
of the invitation to tender for the upgrade of the computing center of the Observatory (see below).
• Large ab-initio production calculations, either conventional or explicitely correlated, were run on the
national supercomputers. We submitted a huge demand in 2005 to boost the calculations of all the
potential energy surfaces related to the “Molecular Universe” FP6 project. We obtained 60000 hours on
the IDRIS and the CEA supercomputers and 100000 hours on the CINES.
• Multi-dimensional potential energy surfaces were sampled by a multi-parametric Monte Carlo procedure.
The 9-D surface for H2O-H2 required 375000 independent geometries, each combining a counterpoise of
3 ab-initio calculations resulting into over a million of short ab-initio runs. This computational challenge
triggered a pluri-disciplinary development of the Grenoble computer grid “CiGri” with the support of
a 3-year CDD funded by the ACI GRID and a strong involvment of the STIC community (INRIA and
IMAG). A CiGrid protopype permitted to gather about 200000 cpu hours on idle PCs and to achieve the
9-D surface for H2O-H2 within two months. Presently CiGri matured to a convivial middleware, and has
been used for classical scattering calculations in our team and by other projects (including optimisation
studies for the MARSIS sub-surface radar observations on Mars Express).
61

• One of us (PV) is strongly involved in the UJF project “CIMENT” (Calcul Intensif, Modélisation,
Expérimentation Numérique et Technologique) funded by the state and the region, which permitted the
creation and upgrade of several computational platforms and associated expertise centers. The originality
of CIMENT is to federate user communities with computer science ones, and was a “cement” for the emergence
of the Grenoble computer grid. CIMENT has funded in 2005 the upgrade of the computer resource
center of the Observatory which is shared between astrophysicists, planetologists, geophysicists, etc. The
new machine is a high performance cluster (30 quadriprocessors, 256 GB of core memory, 4 TB disk, over
0.6 Tflop of peak performance) and will boost all high performance initiatives in the Observatory.
• In the future, we plan to develop tools for harnessing computer grids into the Virtual Observatory, in
particular to trigger multi-parametric modelisations of a set of objets selected by a VO request. Such a
coupling needs a proper specification and scheduling of the related data flow. A pluri-disciplinary project
involving in particular the Observatory and the laboratory ID (Informatique et Distribution) has been
submitted to the ANR in september 2005. Other developments may be carried on within the GRID’5000
national initiative in collaboration also with colleagues from ID.
3.5 Proto-planetary Disks: where Astromol meets FOST
The study of the proto-planetary disks deserves an ad hoc section, because of both of its scientific interest
and the fact that it is also an important field of research for the FOST team. While the FOST Team focuses
mostly on the dust component of the disks, the Astromol team focus is rather the gaseous component. The
two approaches are evidently strictly linked and complementary, and, for this reason, Astromol and FOST
have started a tight collaboration on this theme. This is testified by the beginning of publications in common
(Duchene et al. 2005), the writing of new observing proposals at IRAM (30m and PdB) and Keck telescopes,
the project PAI vanGogh project “Proto-planetary disks” (§2.7) which involves both members of Astromol (CC
and BL) and FOST (F.Menard) and their students.
A notable example of the importance of the dust-gas link in proto-planetary disks is represented by the
interplay between the small dust grains and the gas. Indeed, the gas in the disk governs the dynamics of small
dust grains. Dust grains try to settle towards the midplane, and the gas is critical in slowing down this motion
and countering it by turbulent mixing. Without gas, the dust would collapse (basically within a single orbital
timescale) entirely to the midplane until large (Moon-sized) bodies are able to stirr the disk gravitationally.
With gas present, but without efficient turbulent mixing, the dust would settle within about 10 4 –10 6 years down
to about one gas-pressure scale height (Dullemond and Dominik, 2004 A&A 421, 1075). However, observations
show that disks as old as 10 Myrs contain significant amounts of dust at large heights above the midplane,
demonstrating that the interaction between the grains and the gas is not only taking place, but it is indeed a
crucial aspect of the disk evolution.
The reciprocal is also true: the presence of dust grains has a dramatic effect on the gas structure, thermal
balance, chemistry and dynamics (where all these aspects are strictly inter-related). In the disk upper layers
exposed to the protostar radiation, the radiation is almost totally absorbed by the grains, and the energy
transmitted indirectly to the gas by the collisions with the grains and/or by electrons emitted from grains by
the photoelectric effect (Bakes and Tielens, 1994 ApJ 427, 822). The formation of molecules, which can very
effectively cool the gas, occurs only in the regions where the photoionizing photons are absorbed by the dust.
Further down, in the disk midplane, the molecules freeze out onto the grains and disappear from the gas phase,
giving rise to physical conditions completely different and where different physical processes take over.
In summary, the interplay of gas and grains plays a crucial role in the evolution of protostellar disks, and the
collaboration between Astromol and FOST on this theme aims to address some specific aspects of this interplay.
We take advantage of the complementary expertise of FOST group, mainly on the grains, and the Astromol
group, mainly on the gas, to study the following four issues:
1- The gas in the disk midplane: ionization degree and the gas-to-dust ratio;
2- The grain settling and role of small grains in heating the gas above the midplane;
3- The gas and dust mixing processes;
4- One specific aspect of the grain processing due to the X-rays emitted by the central source.
Note that this collaboration extends to the group of C.Dominik in Amsterdam too, and has received financial
support from the PAI “van Gogh” for the 2005 to 2007 (§2.7). In addition, we have started a collaboration with
the people of the European Synchrotron Radiation Facility in Grenoble to study the chemistry on the grain
62

Figure 3.7: Detection of HDO in the proto-planetary disk surrounding the solar type protostar DM Tau (Ceccarelli
et al. 2005). The figure shows the HDO ground state transition at 464 GHz, which has been observed
in absorption against the continuum emitted by the cold dust in the disk midplane. The fact that the line is in
absorption implies that vapor water forms a blanket covering the entire disk of DM Tau.
surfaces irradiated by X-rays. These experiments aim to simulate the conditions in the proto-planetary disks
surrounding solar type protostars, which are known to be strong X-rays emitters (§3.2.6 and 3.2.7).
In the incoming years, we plan to increase the Astromol involvement in the studies of the proto-planetary
disks, notably their chemical and physical structure. This will also involve a more systematic use of the interferometric
instruments (today Plateau de Bure, tomorrow ALMA), in addition to the already used millimeter
and sub-millimeter single dishes (IRAM-30m, JCMT and CSO).
Meanwhile, Astromol has obtained the following important results on the study of young gas rich protoplanetary
disks:
• The discovery of a way to probe the cold gas in the disk midplane. The midplane of the young protoplanetary
disks that surround Sun-like protostars is so cold and dense that all heavy-elements molecules,
included CO, condense onto the grain mantles, disappearing from the gas phase. Since the bulk of the mass
of the disk resides in the midplane, it is of paramount importance to have a way to probe this component,
for studying how the disk evolves: the condensation of the dust, the dispersion of the gas, etc... Astromol,
using the knowledge acquired in its studies on the molecular deuteration (§3.2.2), has proposed to observed
the ground state transition of the H2D + molecular ion, and obtained the first detections in 2004 (Ceccarelli
et al. 2004). The H2D + observations not only provide the first means to probe the disk midplane, but
they also provide a means to measure its ionization degree, a key parameter in the theories of viscous
accretion of proto-planetary disks (Ceccarelli & Dominik 2005).
• The discovery of deuterated water vapor in proto-planetary disks. In general, water is a key molecule
to observe, because it is a major actor in the cooling of the gas, as well as in its chemical composition.
Deuterated water has the additional interest that the Oceans on the Earth are believed to be formed by the
63

sublimation of water ice trapped either in comets or meteorites or, more in general, in the planetesimals
which formed the Earth. A key parameter in these theories is the HDO/H2O ratio: in oceans it is ten
times larger than the cosmic D/H elemental ratio, close to that of comets, and hundred times smaller than
that observed in solar type protostars (§3.2.2). A big unanswered question is: what is the HDO/H2O in
proto-planetary disks, which contain the material from which planetesimals, meteorites and comets are
formed? Astromol has reported the first detection of HDO in a proto-planetary disk (Fig. 3.7: Ceccarelli
et al. 2005), from which a HDO/H2O ratio (∼ 1%) slightly lower than in protostars has been estimated.
Indeed, the big contribution of these observations is that HDO in the measured quantities should have
not been detected, because H2O and HDO are believed to be almost totally frozen onto the grain mantles
(at least in the region probed by the observations)! Since HDO has been observed, something is reinjecting
water molecules from the grain mantles. Soon after the HDO detection, Astromol showed that
grain mantle photo-desorption from the Interstellar UV field can indeed keep the observed water column
density in the gas phase (Dominik, Ceccarelli, Hollenbach, Kaufman 2005, ApJL submitted).
• The discovery of a small warm disk in a low mass binary system. By using Adaptive Optics (AO) aided
2µm observations at Keck, we revealed the presence of a small ( ∼ < 5 AU), warm (∼ 400 K) and dense ( ∼ > 10 7
cm −3 disk surrounding the more massive companion of the binary system forming T Tau S (Duchene et
al. 2005). The observations detected the CO lines (from J=9 to J=20) in absorption against the source
continuum, a technique already used by other authors for studying a (very) few other disk sources. The
originality and importance of our observations is that, thanks to the coupling with the AO, we could study
a close binary system and demonstrate that the disk of (at least) one of the two protostars is probably
truncated because of the presence of the other protostar. We plan to carry out similar studies in a larger
sample of sources, with the scope to understand how, indeed, the presence of a companion affects the
circumstellar disks of the two composing protostars. More in general, the CO absorption technique is
extremely powerful in characterizing the physical conditions of the gas in the warm layers of the protoplanetary
disks, much more efficient than the mm/submm observations, which only provide one CO J
level at once.
64

Chapter 4
Perspectives
4.1 Overview
Astrochemistry is going to be the keyword of our research in the incoming years. Astrochemistry in its two
major aspects: the molecular composition of the extra-terrestrial matter (§4.2.1) and the basic physical processes
(§4.2.2) that govern it. In a more general context, our activity will expand to “touch” the new emerging research
field of Exobiology, meant as the general study of life in the Universe. On this, our contribution will evidently
be on the Astrochemistry side.
The major new challenge that the Astromol team will face is the study of the molecular complexity in the
interstellar space, and the basic processes linked to it: molecule identification, formation, and evolution, with
emphasis on during the star formation process, from the pre-collapse to the proto-planetary disk phase. This
study will require substantial observational and theoretical progresses, and, consequently, a coordinated effort
at the French, European and world level. Two new instruments, involving world wide consortia, will allow
those major observational leaps and are at the 2007-2010 horizon: Herschel and ALMA (§4.3). Besides, a large
European coordinated effort is on progress to exploit at best the potentialities of both instruments: the EC
FP6 network “The Molecular Universe” (§4.4). Astromol is heavily involved in those three large international
projects, and our activity in the next 2007-2010 will be scientifically and practically dominated by that.
Indeed, the Astromol scientific involvement in these three large projects is heavy, ambitious and important
at the same time. It will require a substantial enlargement of the group to fulfill the engagements and, most
important, to fully exploit all the potentiality of this involvement, which should allow to keep a leading position
of Astromol in the relevant studies (§4.6).
4.2 Scientific goals
In the last four years, substantial progresses have been obtained in our understanding of how stars, notably solar
type stars, form. New signatures and processes of the early formation of solar type stars have been discovered:
e.g. the extreme molecular deuteration, which accompanies the freezeout of the heavy-bearing molecules, and
the birth of hot corinos in the interiors of the envelopes. However, many questions remain open. Here we
mention what we consider some major open questions which Astromol can help to answer in the next years to
come.
From a chemical point of view, it is totally unclear what is the ultimate molecular complexity reached during
the proto-stellar phase. Do pre-biotic or even biotic molecules form? In what quantity? How? From a chemical
and evolutionary point of view, it is even less clear what is the fate of these and any other molecules formed
during the protostellar phase. Do they survive the proto-planetary disk phase? Are they incorporated into the
forming and/or formed planets, via for example bombardment by comets and asteroids? In what quantity?
How?
65

If the chemistry in the first phases of the collapse seems to reach a high level of complexity and sophistication,
much less is known about the chemistry in the proto-planetary disks. At present, only a very few and basic
molecules have been detected (CO, CN, HCO + ...) and in a very few objects. Whether new molecules form in
this phase, either in the gas phase or grain surfaces, is almost totally unknown. Chemistry in proto-planetary
disks is definitively a challenge for the incoming years, and we intend to take on this challenge.
Also, basic questions about the interaction between the forming star and the surrounding environments
remain open. What is the effect of the X-ray/UV irradiation on the circumstellar material? Are the outflows
from the central star only destructive? At what level do they contribute to the molecular complexity? What are
the basic physical processes occurring when the outflowing material encounter the surrounding parent cloud?
Answering all these very basic and important questions require:
i) acquiring new, more sensitive observational data;
ii) developing new, more sophisticated astrophysical models;
iii) carrying out new, more complex computations of basic molecular physics.
The next two subsections will describe in some detail the expected new directions and developments of
our research activity. The two subsections will address the “Star Formation” and “Molecular Physics” themes
respectively.
4.2.1 Star Formation
The overall goal is the study of the molecular complexity during the formation of solar type protostars. More
specifically, we plan to develop the following four major lines of research:
1. Molecular Deuteration in the ISM, pre-stellar cores, and protostars/ In the last few years our group has
had a leading role in the study of the molecular deuteration. Also thanks to our contribution, substantial
progresses have been achieved and the basics processes leading to the observed extreme deuterations is
now (probably) mastered. Therefore, the era of “using” this knowledge to study the relevant physical
processes during the star formation phase as well as in other astronomical sources, even to extra-galactic
in CO depleted
sources, is open. Notably examples are the diagnostic value of the deuterated forms of H + 3
regions, like the center of the pre-stellar cores or the midplane of the young proto-planetary disks. In the
formers, these molecules permit to study the motion, and whether, when and how the collapse sets in. In
the latter, H2D + and HD + 2 allow to measure the ionization degree and the dust to gas ratio (item 3).
2. Molecular Complexity in hot corinos. The existence of the hot corino has been demonstrated just in the
last two years, mostly by the works of our group, in collaboration with WAGOS (§2.7) and people of
IRAM (for the studies with the Plateau de Bure Interferometer). Very little is known so far, because
these objects are difficult to observe, being compact and faint in the lines. The incoming four years
will certainly see an explosion of these studies worldwide, both on observational and theoretical side, on
this subject. Our scope is to keep a prominent role in this field by expanding both our modeling and
observing capacities. It will be a challenge, because several groups have entered the race on this subject
(demonstrating its interest), but we have the right expertise to take this challenge. We are involved, and
often with a major role, in major projects worldwide to obtain the full census of the molecular lines in solar
type protostellar objects: the “Unbiased Spectral Survey of IRAS16293-2422” in the IRAM, JCMT and
APEX bands; the “Spectral Survey of Star Forming Regions Legacy Project” at JCMT; the Herschel-HIFI
Key Program “Spectral Surveys of Star Forming regions” (see details in §4.3). These surveys will allow
to have a complete view of the chemical composition of the solar type protostars and their surroundings
in some cases. In addition, they will allow studies of the kinematics and detailed physical structure across
the regions, thanks to the peculiarity of the chemical composition and line excitation, different in different
regions. In addition, we have embarked in the systematic study of the hot corino at high spatial resolution
with PdBI, to probe and measure their sizes and molecular content. In summary, the incoming years will
see likely a change of these studies from pioneer to fully established, and our group is in a good position
to be a major actor in this play.
3. Proto-planetary Disks. We plan to invest more and more in this field. In particular, we have new lines
of research that we intend to pursuit, as detailed in the following. i) We have shown that the deuterated
forms of H + 3 (notably the ground state transition of H2D + ) can be used to measure the ionization degree
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in the midplane of young disks surrounding solar type protostars and their dust to gas ratio, two key
parameters in the theories of disk evolution and planet formation. This is a very recent result, and we
certainly plan to fully exploit this new line of research, by carrying out systematic surveys, both with
single dish telescopes and modeling. So far CSO, SMA (since spring 2005) and APEX (since October 2005)
permit these observations, but in a not too far future the ortho-H2D + line used for these studies will be
accessible with ALMA. In addition, the para-H2D + , as well as both ortho and para lines of HD + 2
will also
be accessible with the advent of Herschel HIFI and SOFIA. ii) The detection of deuterated water by our
group has also open a new way to probe the history of the dust grains, and specifically the fate of their icy
mantles during the proto-planetary phase. Again, this is a field just started and that clearly deserves a full
exploitation. One by-product is the prediction of the observability of water vapor in proto-planetary disks
with Herschel, observations which will become available in the incoming four years. iii) More in general,
we plan to expand our observational and modeling capabilities on the chemistry of proto-planetary disks,
by applying, exporting and expanding what we have learned so far in the studies of the previous phases.
Notable examples are the chemistry of sulfur, oxygen and carbon in proto-planetary disks, which haven’t
been exploited so far, and on which we have a good expertise.
4. The interaction of the forming star with the surroundings: outflows and X-rays Our group is currently
investing stronger efforts in the studies on protostellar outflows. The emphasis is put on both the observational
and theoretical sides. Observationally, the goal is to determine the physical conditions (velocity,
density, temperature) in the entrained gas and in the shock regions, based on the H2 line emission, accessible
in the mid- and near-IR, and the emission of the high-excitation line of molecular tracers in the
mm/submm windows. Theroretically, it is necessary to improve the existing models to a) reach a multidimensional
(2D/3D) description, required to provide a realistic treatment of the leading bow in outflows,
b) make predictions not only on the (velocity-integrated) line flux but on the line profiles. These aspects
are undertaken in collaboration with colleagues at LERMA in Paris (G. Pineau des Forets, S. Cabrit)
and at DAMIR in Madrid (J. Cernicharo, J. Martin-Pintado). A large-scale survey of the CO emission
in TMC 1 has been undertaken, in collaboration with IRAM colleagues (K. Schuster, C. Thum) to search
in an unbiased way for molecular outflows and their protostars, down to the smallest scale size, comparable
to the cooling lengthscale in MHD shocks (10 16 cm), and investigate their impact on the global star
formation in the cloud.
5. X-rays: from astronomy to the laboratory
• Among the unsolved questions is the problem of the X-ray emission from the youngest protostars (socalled
Class 0, still in a state of gravitational collapse). Up to now, and in spite of extensive searches on
∼ 20 low-mass star-forming regions, no Class 0 protostar has been detected in X-rays (Montmerle et al.,
in preparation). This is most likely due to the fact that the extinction of their dense envelopes is very high
(AV > 500). With a careful summing of existing XMM and Chandra observations, it is however hoped to
at least set stringent upper limits to the intrinsic X-ray luminosity. Another way to attack the problem
is, here also, to look for indirect evidence in the mm range, in the form of specific radicals (like HCO +
or DCO + ) that could be the signature of internal X-ray irradiation. Except perhaps in one case, IRAS
16293 (see Ceccarelli et al. 2002b), no evidence was found so far and more observations are planned. Here
again, the ultimate goal is to measure the ionization fraction of the envelope and the resulting coupling
between the material and magnetic fields.
Similar observations will be conducted in and around more evolved sources, from evolved protostars (Class
I) to T Tauri stars still embedded in molecular clouds, for which the X-ray luminosity is measured and
can be compared with chemical tracers of irradiation.
• Another approach is to do laboratory experiments. Several years ago, T. Montmerle co-supervised a
PhD thesis (S. Gougeon, 1998) which featured X-ray irradiation experiments on model interstellar dust
grains (PAHs, coals, etc.) using the ESRF facility in Grenoble, to compare with ISO data in star-forming
regions. The laboratory IR spectra from irradiated grains proved to be complex and difficult to interpret,
but revealed many interesting features (like spectral lines associated with certain bonds like C-C, C-H,
etc.), some evolving with the irradiation dose, others not. On the other hand, the X-ray energies at ESRF
(nearly 10 keV) tend to be high with respect to typical stellar energies (a few keV), precluding a direct
comparison with astronomical data. It is envisaged in the current prospective period (2007-2010), to set
up follow-up experiments at the SOLEIL facility, which offers softer X-rays, and compare the resulting IR
spectra with modern, more sensitive astronomical IR spectra such as obtained by Spitzer.
Along the same lines, a fruitful collaboration with French meteoriticists and experimentalists (e.g., M.
Gounelle from Orsay, M. Chaussidon from Nancy, H. Leroux from Lille, possibly also E. Quirico from
LPG) has been established, with the aim of federating experiments in various related fields of astrophysical
interest nationwide (approved proposal to PNPS).
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4.2.2 Molecular Physics
The theoretical advances made by our group during the past four years have been mainly focused on low-energy
excitation processes involving small polyatomic molecules in collisions with H2 and electrons. In addition to their
astrophysical relevance, our works have provided significant advances of broad interest in molecular physics.
The next challenges we whish to address are relevant to higher temperature processes and larger molecules. This
evolution of our theoretical activity naturally follows the current trend of observing more and more complex
molecules in more and more “harsh” astronomical environments.
1. Ro-vibrational excitation A particular challenging issue of current collisional studies is the computation of
rovibrational rates for polyatomic species. These rates become astrophysically relevant at relatively high
temperature (typically above 300 K) where a large number of rovibrational quantum channels open up.
Thus, even for a light molecule like water, the calculation of rovibrational cross sections at the relevant
energies is currently computationally impossible at the close-coupling “exact” level of theory. Furthermore,
approximate quantum methods such as the widely used vibrational close-coupling rotational infiniteorder-sudden
(VCC-IOS) approximation are questionable for molecules with relatively large rotational
constants, as we have shown for water in a recent paper (Faure et al., JCP 2005). The reliability of
standard quantum/classical approximations must therefore be assessed and controlled in a number of
representative cases. In this context, we note that H2O and HC3N are two very interesting candidates as
they present both very different rotational constants and vibrational frequencies. As a result, our next
short-term theoretical efforts will be put on the treatment of the rovibrational dynamics of these and other
larger systems.
In addition to these developments, the relevance of rovibrational processes in actual astronomical sources
must also be investigated. Our preliminary results for H2O−H2 (Faure et al. 2005) have thus shown that
the collisional excitation of the bending mode of water should be efficient only for densities larger than
about 10 10 cm 3 s −1 . Such high densities are found for example in the envelopes of late-type stars. For other
molecules with low vibrational frequencies, however, critical densities should be significantly lower. As a
first step, qualitative investigations based on the expected orders of magnitude should thus help to clarify
the relevance of the various collisional processes in environments of moderate to high temperatures.
2. Heterogeneous reactivity In spite of numerous recent experimental and theoretical studies, grain surface
chemistry is still far more poorly understood than gas-phase chemistry, notably because of our lack of a detailed
knowledge of the physical nature of the surface. The two major problems faced by astrochemists are
currently: (i) the detailed mechanisms for the sticking/reaction/desorption processes on low-temperature
interstellar surfaces and (ii) the dependence of these processes on the morphology and structure of the
grains. Given the high dimensionality of these dynamical problems, classical dynamics simulations are
particularly suited. Quantum effects such as tunneling under diffusive barriers might however prove crucial
for some reactive processes at very low temperature. Inclusion of “local” quantum effects in large-scale
classical simulations is thus a major issue we wish to address in the upcoming years. The specific astrophysical
problems we wish to tackle are directly related to recent observational results of our group: (i)
how hydrogenated molecules (H2O, H2CO, CH3OH, etc.) form on grain surfaces? (ii) how different is
it for deuterated species? (iii) what processes govern the depletion of molecules like CO and N2 in cold
pre-stellar cores?
In addition to these theoretical developments, the possibility of carrying out original experiments on
interstellar ice analogs has been recently discussed with Bernard Schmitt and Eric Quirico, specialists of the
synthesis, characterisation and properties of ices of planetary interest at the Laboratoire de Planétologie
de Grenoble. A collaborative project might be structured around the sticking and desorption processes at
work in the cold interstellar medium.
3. Towards larger molecules : far infra-red or micro-wave ? While the observation of small molecules, 2
to 6–10 atoms is now routine (from OH to (CH3)2O or HC7N) there is a natural tendency to look for
larger molecules, comprising cycles or several functionalities. The obvious goal is to get nearer and nearer
to molecules of great chemical importance (like 5-membered or 6-membered heterocycle) or molecules
pertain to biochemistry, like sugars, amino-acids, . . . Observing these molecules is rather difficult today,
for several, not mutually exclusive, reasons: (i) Evidently their abundances are small (ii) Being heavy
molecules, their rotational constants are small and they are usually asymmetric tops; consequently their
rotational lines for moderate J lie very low in frequency in domains that may be not so well explored
(iii) The oscillator strength is divided into many low frequency lines, rendering the observations all the
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more difficult (iv) The region where the highly excited J lines fall may be congested and these spectra
are sometimes not known experimentally, at least with high precision at high J.
Another path leading to the observation of large molecules comes from the far infrared spectral region
(ν ∼ 0.5 · · · 2 THz, k ∼ 15 · · · 60 cm −1 ). This range of frequency corresponds to floppy bending modes or
torsional modes. Some are experimentally known but most are not. The advantage of the THz modes s
their higher frequency, leading to higher A Einstein coefficients, hence higher sensitivity. Also, it is possible
that congestion problems would be less severe. These considerations remain however still speculative and
necessitate a joint theoretical and experimental effort (the Soleil light source may be very valuable).
A new generation of out of atmosphere telescopes, and principally Herschel (HIFI instrument) will open
this spectral window. It is essential that our team takes part in the large molecule search that these
instrument will allow.
4. Gas-phase reactivity: revisiting reaction rates Large models of gas phase chemistry have been only partially
tested in their various aspects. Here we mention some major issues:
• What is the relevance of present-day rates, is it worthwhile to compute some with a good precision?
Many rates are guessed from analogous reactions. How important is it to know the rate evolution
with temperature, in particular for neutral-neutral reactions.
• What is the structural stability of the differential equation system that governs the evolution of
species populations. Some work in this realm has been undertaken by V. Wakelam.
• How interesting is it to simplify system and analyze some carefully chosen subsystem ?
An interaction with specialists in dynamical systems theories would be particularly useful. In this context,
Astromol (LW, PV, AF) received PCMI financial support for leading en effort in this field.
5. Transition state theory (TST) Many theoretical problems remain open, most of which with important
applications in theoretical chemistry but also in celestial dynamics. In particular, progress must be made
in TST for chemical reactions on surfaces or with many degrees of freedom.
4.3 The involvement in the large international projects: Herschel
and ALMA
Astromol is heavily involved in two big international projects, defined as major milestones for the French
Astronomy: the European satellite Herschel Space Observatory (HSO) and the sub-millimeter interferometer
ALMA. The two projects will start working in the next few years: Herschel in 2008, and ALMA soon after.
Before the instruments become operative, Astromol is actively participating to and will continue to work on
their preparation.
More specifically, members of Astromol are official or unofficial co-Astronomers of the HIFI consortium.
They are participating to the preparation of a Key Program of Herschel, entitled “Spectral Line Surveys of
Star Forming Regions” (requiring about 300 hours of HIFI Guaranteed Time). The program consists in the
observation of the entire (or most) spectral band of HIFI, at the highest possible spectral resolution (∼ 1 km/s),
of a number of representative sources of star formation. The Key Program is leaded by a member of the Team
(C.Ceccarelli). Table 4.1 summarizes the involvement of Astromol in this program. Note that C.Ceccarelli is
also the leader of the “HIFI Star Formation Group”, which proposes three HIFI Key Programs: “The water in
Star Forming Regions”, “Orion and SgrB2 Star Formation Regions with HIFI”, and the “‘Spectral Line Surveys
of Star Forming Regions” already mentioned.
After the launch of Herschel, Astromol will be evidently very active in the exploitation of the data. Indeed,
we expect that this will be a major involvement for our group, and even a challenge, for the amount of expected
data and information. To give an idea, based on the ground-based observations, we expect to detect around 10
lines per GHz ,in the Class 0 source IRAS16293-2422. On the ∼ 1500 GHz band of HIFI this will provide ∼ 10 4
lines from different molecules! Evidently, this is a major challenge. Two aspects make it a “major challenge”:
i) the handling of such a massive amount of data; ii) the interpretation of so many lines, many of which from
molecules whose physical proprieties have not yet fully studied. Our group is already preparing itself for this
challenge, developing the procedures to handle all this information in an efficient way.
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Source Herschel Time Astromol
Class (hours) members
Pre-Stellar Core 25 CC, BL
Class 0 low mass 50 CC, BL
Class 0 intermediate mass 50 CC, BL
Outflows 30 BL, CC
Table 4.1: Herschel HIFI Key Program “Spectral Line Surveys of Star Forming Regions”
. Summary of the scientific topics, and the amount of Herschel guaranteed time devoted to each of them. The
third column lists the participation of Astromol members to each topics: CC=C.Ceccarelli, BL: B.Lefloch.
In this respect, Astromol is involved in the project “Unbiased Spectral Survey of the solar type protostar
IRAS16293-2422” (leaded by E. Caux, CESR Toulouse), for which about 300 hours of IRAM and JCMT time
have been allocated (and used). Also, Astromol is involved in the JCMT Legacy Program “Spectral Line Surveys
of Star Forming Regions” (leaded by G.Fuller, Manchester, UK) which has been allocated about 200 hours.
In addition, a key aspect in this preparation is the participation to the European Network “The Molecular
Universe”, described below (§4.4). Note that, Herschel HIFI and ALMA are very complementary instruments.
Much of what we are developing and learning for Herschel HIFI will also be useful in the exploitation of ALMA,
and our group will not make this opportunity to be spoiled. To support our statement, in the last year we have
been developing a tighter collaboration with people at IRAM, notably the collaboration with Roberto Neri on
the exploitation of the Plateu de Bure to observe organic molecules in young embedded protostars as well as in
disks (as evident from the list of publications of our group).
4.4 The European Network “The Molecular Universe”
The RTN FP6 European Network “Molecular Universe” has been funded for 2005-2008 with the following
ambitious objectives: “This highly interdisciplinary network combines European researchers from 9 countries and
21 laboratories in the areas of laboratory spectroscopy, laboratory astrochemistry, molecular quantum mechanical
studies, astronomical modellers, and experts on data bases and web interfaces. By training future researchers
and by integrating European research efforts in the field of molecular astrophysics, Europe will be well poised
to take advantage of the planned European ground-based (such as Bure extensions and ALMA) and space-based
missions (such as Herchel-HIFI).”
France is strongly represented in this network, thanks to the active PCMI community. And among the
French groups, Astromol is highly involved.
In Task 1, “Molecular Complexity in Space”, we are involved in the three topics and in 11 milestones.
Namely for Topic 1.1, “Water in the Universe”, we are involved in milestones 1.1.2 to 1.1.7:
• 9D-Surface + rotational cross sections of H2O + H2
• 6D-Surface + rotational cross section of H2O + H/He
• Ro-vibrational cross-sections H2O + H/He/H2
• Ro-vibrational cross sections of HDO + H/He/H2
• Experimental measurement of state-to-state cross-sections for H2O + H2 and probing theoretical predictions
• Radiative transfer and excitation of H2O emission in photon dominated regions
Then for Topic 1.2, “Carbon Chemistry”, we are involved in milestone 1.2.8:
• Ab-initio intra and inter molecular interactions for HC3N and dynamics
For Topic 1.3, “Deuterium chemistry”, we are involved in milestones 1.3.3, 1.3.4, 1.3.6, and 1.3.7:
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• 12D-Surface of NH3 with H2
• Rotational excitation of NH2D, ND2H with H2
• Experimental measurement and theoretical predictions of cross-sections for NH2D + H2
• Surface of H2CO with H2 for excitation studies of HDCO / H2CO
In Task 2, “Chemistry in Regions of Star Formation”, one of us (CC) is the task manager of the network,
and we are also involved in Topic 2.2, “Nitrogen Chemistry as tracers of protostellar condensation” for milestone
2.2.7:
• Sticking and desorption processes in dark cloud/proto-stellar models: impact on gas abundances and
ionization state
Finally in Task 3, “Databases and Web interfaces”, we are involved in milestone 3.2:
• Simulation tool combining astrophysical models and molecular data bases to produce synthetic spectra
for comparison with observations
Obviously the fulfillment of our commitments in the Molecular Universe network constitutes a large fraction
of the prospective of the Astromol team until the end of 2008.
We also plan to extend our contributions to milestone 3.2 to applications related to the Virtual Universe.
In particular, as already previously explained, we plan to develop original services for coupling the VO grid
to computer grids, and thus facilitate the systematic exploration of astrophysical models on a wide range of
objects selected by the VO requests.
4.5 Cosmology: a new frontier for Astromol ?
Cold interstellar dust and cosmology have a large interplay in the millimetre electromagnetic spectrum. Synergy
between these two fundamental fields in astrophysics (one’s signal is the noise source of the other) is also found
in instrumental, observational and data reduction techniques.
In the star formation process, one of the main topics in astrophysics, dust is both acting in it and tracing
it. Acting in it, because dust can evacuate some of the gravitational energy in some phases of the pre-stellar
collapse and dust is strongly coupled with the interstellar molecular gas, a central topic of Astromol. Tracing
the star formation process, because modern instrumentation, basically cold bolometers in the (sub)millimetre
domain, allows us to map dust, hence gas, with an equivalent column density as low as 10 22 H m −2 .
In the course of the present activity period, F.-X. Désert continued working on bolometer developments
in preparation for the Archeops balloon mission, to study the submm emission of the whole sky, with two
main constituents: (i) a foreground galactic dust emission; (ii) a cosmological microwave background (CMB),
basically at 3 K but with minute dust emission fluctuations (∆T ∼ 10 −4 at a few 100 GHz) tracing the earliest
episodes of galaxy formation in the recombination era.
While was F.-X. Désert formally belonging to the Sherpa group in the previous LAOG structure, it became
evident from this work that he should eventually join the Astromol group, for at least two reasons. First,
while mainly devoted to comological objectives, the Archeops mission is also rich in galactic dust astrophysics
implications (Benoît et al. 2004), and more generally, on cosmic dust in a variety of environments (submm
excess in the CMB possibly caused by dust created and ionized by Population III stars: Elfgren & Désert 2004).
Second, the associated instrumental work on bolometers is also in the submm range, and prepares for the High
Frequency Instrument (HFI) on Planck i.e., the companion satellite to Herschel used by the Astromol group.
This instrument includes a dilution cooling system made in Grenoble (Air Liquide and CRTBT), allowing
to obtain high resolution all-sky maps of cold dust with unprecedented sensitivity. In collaboration with
CRTBT and LPSC in Grenoble, and with the whole Archeops team, we are completing the publication of
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several important studies that anticipate the harvest of Planck results: 1) polarization of the emission of diffuse
interstellar dust, 2) anomalous dust emissivity and 3) a catalogue of about a hundred (13 arcmin size) bright
point sources. These results were obtained from a 12-hour Archeops balloon flight in the Arctic sky in 2002,
using HFI technology (Benoît et al. 2003a, b; Tristram et al. 2005)
The Planck satellite will allow the ultimate measurements of CMB anisotropies with a sensitivity about ten
times better than the WMAP achievement and an angular resolution 3 times better. An accurate determination
to within one percent will be obtained for the ten or so cosmological parameters describing our Universe (Hubble
constant, curvature, cold, neutrino, and baryonic matter content, dark energy and its equation of state,...). We
are involved in the ground-based and in-flight calibration of HFI as well as in some data processing pipeline, in
collaboration with other Grenoble laboratories (Santos-Renault team at LPSC, Benoît-Camus team at CRTBT).
In the coming years, we intend to make an optimal use of the Archeops then Planck submillimetre maps
for in-depth scientific results. In the mean time, we take part in the developments of new CCD-like bolometer
cameras, in particular for the IRAM 30m telescope (the program DCMB, led by A. Benoît, is funded by INSU,
PNC, PN Astroparticules and CNES). These cameras could provide a useful complementary tool to the space
experiments (Herschel, Planck) and Alma which will all arrive between 2007 and 2012.
4.6 The needs of Astromol : accretion and recruitment
Our plans are admittedly scientifically very ambitious. Our scientific record endorses our ambitions, and pushes
us towards far reachable goals. However, to fully exploit the capacities and knowledges we have developed so
far, and to keep having a leading role in our research lines, we evidently need to become bigger in terms of
permanent and not-permanent staff, and not by a number of one. We aim to enlarge our group by accreting
senior researchers and, possibly Post-Docs (which, as known, are extremely rare in France). However, there is
an evident need to increase the number of permanent stuff members by hiring young researchers. In the past we
have been forming several of them, and good candidates are indeed available. To be more specific, the following
major areas require urgently young permanent researchers in the next four years (of this quadriennal):
• At the short horizon 2006-2010, we have the big challenge of being able to scientifically fully exploit the
opportunity we have been creating for ourselves and France of the Herschel HIFI Key Program “Spectral
Line Surveys of Star Formation Regions”. Note that this is the largest Herschel HIFI Key Program in
terms of hours leaded by a French researcher and with the largest amount of French HIFI Guaranteed
Time. We feel therefore mandatory for us to make it a scientific success. While we have been developing all
the important tools to exploit at best this occasion (involvement in “The Molecular Universe” European
Network -§4.4-, spectral surveys with ground based millimeter and sub-millimiter telescopes -§4.3-...),
there is clearly an urgent need of accretion in terms of permanent staff. Specifically, we need to hire
two young researchers with experience in molecular line emission, line identification and modeling of
protostellar environments, the first as soon as possible (2006/2007), to participate to the preparation of
the programs (doing observations, modeling and interpretation of the data), and the second one once
Herschel has launched (2008/2009) to reinforce Astromol in the exploitation of the Herschel HIFI data.
• The physics and chemistry of the proto-planetary disks is a hot field of research where LAOG has a
prominent position in the international community. Astromol entered this field of research only recently,
but with successes which authorize ambitious plans (§3.5). In addition, the proto-planetary disks is
also a theme of research of the FOST team, and the interplay between the two teams has been already
very fruitful. This and the complementarity of the different observational tecniques (from X-rays to IR
to radio observations) makes LAOG a privileged and unique site in France for developing this line of
research, notably the chemistry in proto-planetary disks. However, in order to capitalize and expand the
Astromol activity on the proto-planetary disk field of research, Astromol needs additional manpower, and
particularly on the modeling of the chemistry.Considering the timescale of the evolution of our research,
we envisage that a young researcher will be in demand by 2007/2008.
• In the context of the ALMA exploitation, IRAM collaboration and the LAOG-IRAM European Center of
Expertise for Interferometry in Astronomy (CEXIA: see Executive Summary) Astromol is strongly solicited
to take a major role, as it is the natural interlocutor with IRAM and its research heavily does and will
use millimeter (and submillimeter) interferometric facilities. Again, Astromol has indeed the capacities
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for doing that, but we are limited by the limited manpower we dispose. In order to appropriately answer
to the demand, the hiring of a young researcher expert in interferometry is required by 2008/2009.
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Chapter 5
Selected Publications
• Discovery of Deuterated Water in a Young Protoplanetary Disk
Ceccarelli, C.; Dominik, C.; Caux, E.; Lefloch, B.; Caselli, P.
Astrophysical Journal Letters 2005, 631, L81
• Faure, Alexandre; Valiron, Pierre; Wernli, Michael; Wiesenfeld, Laurent; Rist, Claire; Noga, Josef; Tennyson,
Jonathan
A full nine-dimensional potential-energy surface for hydrogen molecule-water collisions
Journal of Chemical Physics 2005, 122, 221102
• Shock-induced PDR in the Herbig-Haro object HH 2
Lefloch, B. ; Cernicharo, J.; Cabrit, S.; Cesarsky, D.;
Astronomy and Astrophysics 2005, 433 ; 217-227
• Improved algorithm for triple-excitation contributions within the coupled cluster approach
Noga, J.; Valiron, Pierre
Molecular Physics 2005, 103, 2123-2130
• Geometry of phase-space transitions states: many dimensions, angular momentum.
Wiesenfeld, L.
Adv. Chem. Phys. 2005, 130A, 217
• Near-Arcsecond Resolution Observations of the Hot Corino of the Solar-Type Protostar IRAS 16293-2422
Bottinelli, S.; Ceccarelli, C.; Neri, R.; Williams, J. P.; Caux, E.; Cazaux, S.; Lefloch, B.; Maret, S.;
Tielens, A. G. G. M.
Astrophysical Journal Letters 2004, 617, L69
• Detection of H2D+: Measuring the Midplane Degree of Ionization in the Disks of DM Tauri and TW
Hydrae
Ceccarelli, C.; Dominik, C.; Lefloch, B.; Caselli, P.; Caux, E. Astrophysical Journal Letters 2004, 607,
L51
• The H2CO abundance in the inner warm regions of low mass protostellar envelopes
Maret, S.; Ceccarelli, C.; Caux, E.; et al.
Astronomy and Astrophysics 2004, 416, 577
• Electron-impact rotational excitation of water
Faure, Alexandre; Gorfinkiel, Jimena D.; Tennyson, Jonathan
MNRAS 2004, 347, 323
• CO Depletion and Deuterium Fractionation in Prestellar Cores
Bacmann, A.; Lefloch, B.; Ceccarelli, C. ; Steinacker, J.; Castets, A.; Loinard, L.;
Astrophysical Journal Letters 2003, 585 ; L55-L58
• A Keplerian disk around the Herbig Ae star HD 34282
Pietu, V., Dutrey, A., Kahane C.
Astronomy and Astrophysics 2003, 398, 565
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• Determination of the gas-to-dust ratio in nearby dense clouds using X-ray absorption measurements
Vuong, M. H.; Montmerle, Thierry; Grosso, Nicolas; Feigelson, E. D.; Verstraete, L.; Ozawa, H.
Astronomy and Astrophysics 2003, 408 ; 581
• Rotational transition states: relative equilibrium points in inelastic molecular collisions
Wiesenfeld, L.; Faure, A.; Johann, T.
Jour. Ph.B 2003, 36, 1319
75

Part IV
TEAM FOST
The first image of a planetary mass companion outside our solar system, observed with
NAOS on the VLT
77

Chapter 6
Introduction of the team & Science
Results
6.1 FOST: a large research group on the formation of Stars and
Planets, and the Lower Mass Function
Since the last review committee visited LAOG, three groups joined efforts to form what is now known as team
FOST. FOST is an acronym standing for “FOrmation Stellaire, objets SubStellaires, and Systèmes planéTaires”,
that is often contracted to “Star and Planet Formation” for practical purposes.
FOST is currently the largest of four teams at LAOG. It houses 20 staff members (including one on leave at
CFHT), 3 post-docs, and 14 PhD students (in full or shared supervision). FOST evolves quickly. Since 2001,
four permanent positions were allocated to our team: Gaspard Duchêne (CNAP), Nicolas Grosso (CNRS),
Jean-Charles Augereau (CNAP), and Estelle Moraux (MdC-UJF). 5 post-docs visited us: David James (now
a post-doc at Alabama State University), Tim Kendall (now assistant professor at University of Hertfordshire,
UK), and Hideki Ozawa (now postdoc at Osaka University, Japan). Sylvia Alencar (Brazil) and Willem-Jan de
Wit (Holland) are the current FOST post-docs. At the time of writing, Claudio Zanni is about to join us in the
framework of JETSET. 7 PhD dissertations were defended successfully since 2001.
The spectrum of FOST’s activities is broad. It spans the study of solar-like young stars and their environments
(disks and jets) as well as the study of lower mass brown dwarfs and free-floating “planets” in nearby star
forming regions. It also covers the study of the more evolved so-called “debris disks” now found around stars
of all masses, from A to M, and a census of the low-mass population of the Solar neighbourhood including, in
particular, multiplicity and the search for extrasolar planets by radial velocity. All these efforts have a common
long term goal: Our Origins, identify and understand the mechanisms by which stars and planets form and
evolve.
In the following sections, our main activities are described. The presentation aims at highlighting not all,
but some important results obtained by FOST members recently. Hopefully, the presentation will also clearly
show that within FOST, the activities are now tightly the various intertwined and the boundaries between the
former groups that merged to form FOST are vanishing quickly, both in terms of scientific goals and in terms
of human resources. This is felt as a success by all of us. This feeling is further strengthened by the superb
(and still growing) synergy between FOST and all other teams at LAOG: with SHERPAS for the star-disk
interaction and jets physics; with ASTROMOL for the coupling of dust and gas studies in protoplanetary disks,
and with GRIL for providing some of the key instruments to reach our science goals.
6.2 Scientific Highlights
• Direct images of planetary mass companions around 2 objects in young nearby associations (2MASSW J120733
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393254 (5MJup at 55 AU) & AB Pic (13-14 MJup at 250AU)). These results were obtained with the
NACO/VLT Adaptive optics instrument, built in part at LAOG. (Chauvin et al. 2004, 2005a, 2005b.)
• Dynamical masses: First astrometric mass determination for a planet, around Gliese 876b: 1.89±0.34MJup
(Benedict et al. 2002). Similarly, astrometric meaurements of stellar masses in binary systems. Accuracies
on the mass of a few percents are reached on nearby L dwarf 2MASSW J0746425+2000321 (Bouy et al.
2004) and ∼ 10% for young stars V773 Tau, DF Tau, and TWA 5 (Duchêne et al. 2003).
• The Universality of the “present day” Mass Function observed down to at least 30 Mjup (the
sensitivity limit of the surveys carried) in several young open clusters (e.g., Moraux, Bouvier, & Clarke
2005). Improvements, i.e., completeness down to a few MJup, is expected soon after the commissioning
of WIRCAM/CFHT, built partly at LAOG.
• The very inner structure of young B star MWC 297 revealed by NIR interferometry. For the first
time, the respective contributions from the disk and the wind are separated spatially & spectrally within
the inner 1AU of the central source. These results were obtained with the interferometric near-infrared
three- telescope recombiner AMBER/VLT, built in part at LAOG. (Malbet et al. 2005).
The highlights listed above will also be found in the executive summary of the present document. It is
significant that three of these four highlights from FOST were obtained with technology “made in LAOG”
and also obtained by young members of FOST. This is a direct consequence of the good adequation (the term
synergy being probably more appropriate) between the science goals of FOST and the activities of the technical
group. However, FOST being a large group, it is difficult, and ultimately unfair to many of its members, to
limit the number of highlights to a short handful for a period of 4 years. Below are listed a few other interesting
results.
• Discovery of Earth-mass planets around Mu Arae (14 Earth masses, Santos et al. (2004)) and around
the M dwarf Gliese 581 (17 Earth masses, Bonfils et al. (2005), in press).
• Spatially resolved emission from Nanograins and PAH’s in disks of intermediate mass stars evidenced
by mid-IR spectroscopy and direct imaging. (Augereau et al. 2005, in prep.; Ménard, Pinte, &
Duchêne, in collaboration with CEA/Saclay). The continuum thermal infrared imaging of T Tauri
disks, seen in scattered light up to 12µm in this case, revealing the first clear observational signs of vertical
dust settling. (McCabe et al. 2003).
• Monitoring of X-ray variations in V1647 Ori (McNeil’s nebula) to study the star-disk interaction
zone during an enhanced accretion phase: evidence for a powerful accretion shock on the photosphere of
a low-mass star. (Grosso et al. (2005)).
• The non-steady state of the accretion and ejection processes revealed at all timescales covered
by our monitoring campaigns (from a few minutes to years). See Dougados et al. (2005) for a review.
• Survey for Binaries in embedded protostars to identify the initial conditions for star formation /
early stellar evolution immediately after fragmentation of the molecular core. (Duchêne et al. 2004).
• Dynamical models of the circumbinary ring aroung GG Tau to explain the puzzling sharp outer edge.
(Beust & Dutrey (2005a,b)), and of the very young debris disks HD 141569 to search for traces of planets
(Augereau & Papaloizou (2004)).
• Discovery of several new brown dwarfs in the Taurus cloud, helping to show that the number
fraction of brown dwarfs in this low density star forming region is consistent with the ones in denser
regions like Orion.(Guieu et al., 2006, A&A 446, 485).
6.3 Selected Topics in Star Formation and Early Stellar Evolution
Accretion disks are key ingredients in the cocktail of events that lead from the collapse of a molecular cloud to
the formation of a solar-like star. They are the entities by which the infalling material transits on its way to
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the central star. They regulate the distribution of angular momentum, provide the material and the energy to
launch jets, provide the raw material to form planets, etc... Not surprisingly, a large fraction of our activities
has been historically devoted to the search and study of these disks around young solar-like stars. With time
however, our spectrum of activities has broadened. Today, it includes the study of both to the inner parts of
these disks and the study of the mass-loss phenomenon, itself strongly coupled to the accretion process, and
possibly to the star-disk interaction zone. Disks around brown dwarfs and A stars are also considered now,
further broadening our spectrum.
To carry this research, LAOG proved to be a unique place. For example, to study the mass-loss process,
strong ties with SHERPAS gave us access to coherent, cutting edge physical models of MHD disk winds able to
predict jet rotation rates and emission-line ratios (Pesenti et al. 2004) (both now observed) while the presence of
GRIL and the technical group gave us prime access, very early on, to the best available high angular resolution
data obtained with adaptive optics and interferometry. In the sections below, we describe some of these results.
6.3.1 Observation and models of young accretion disks
The Outer dust disk
Studies of the properties of T Tauri disks were initially based on the analysis of the spectral energy distribution
(SED) only, for lack of available images (e.g., Beckwith et al. 1990, AJ, 99, 924). The first images of disks
seen in scattered light became available in 1996 with HST in the optical and ground-based adaptive optics in
the near-infrared (Burrows et al. 1996, ApJ, 473, 437 for HH 30 with HST; Roddier et al. 1996, ApJ, 463, 326
for GG Tau with AO). Maps of disks at longer wavelengths became available roughly at the same time with
millimeter interferometers (e.g., Dutrey et al. 1996, A&A, 309, 493).
Today, SED fitting still provides useful constraint on the disk structure, (e.g., inner radius, flaring surface,
vertical inner rim, ec) and to some extent on the dust properties (size distribution, opacity law) but the more
difficult image fitting, coupled with SED fitting, is proving much more powerful.
After being very active in searching for new disks in the previous 4-year period, but see Chauvin et al.
(2002) for the recent discovery of the edge-on disk Lk Hα 263 C, our efforts are now going into improving the
wavelength coverage of known disks, from scattered light images in the optical and near- to mid-infrared, e.g.,
Stapelfeldt et al. (2003); Duchêne et al. (2004) to thermal emission maps in the millimeter range, e.g., (Duchêne
et al. 2003). Our image fitting models, largely improved by Christophe Pinte (ongoing PhD thesis), is based
on a powerful 3D Monte Carlo radiative transfer scheme. The analysis and publication of several datasets is
currently underway.
In the visible and near-infrared (shortwards of 2µm), we have used VLT and HST to gather additional
images of several known disks. This effort involves long standing collaborations with Karl Stapelfeldt (JPL)
and Andrea Ghez (UCLA).
Simultaneous multi-wavelength image fitting is important because the scattering properties (i.e., albedo,
phase function, polarisation) of dust grains depend on wavelength and these model offer a better probe of the
grain size distribution and disk parameters than fitting a single image does.
Comparing our previous HST image of the edge-on disk around HK Tau B (Stapelfeldt et al. 1998) to a
2.2µm image of the system that we obtained with VLT’s NAOS (see Fig.6.1) shows that the dust grains in that
disk are at least as forward-throwing in the near-infrared than they are in the visible (Ménard et al. 2006),
clearly showing the presence of larger grains. This result is further supported by the detection of scattered light
at 12 microns (McCabe et al. 2003, see Fig.6.1).
This result is extremely interesting as grains several microns in size are needed to produce significant scattering
at 10µm. This encouraging results prompted us to obtain more observations in the mid-infrared (3–20 µm)
on other disks, in particular during the first public observing campaign offered with the laser-guided adaptive
optics systems on the Keck telescope and during commissioning of VISIR at the VLT. In all disks observed so
far, we have revealed the presence of much larger dust grains than those found in the interstellar medium.
In addition, in the GG Tau circumbinary ring, Duchêne et al. (2004) demonstrated that the scattered
81

2.2 µ m
0.5"
11.7 µ m
Figure 6.1: Left Panel: K-band image of the edge-on disk HK Tauri B ontained with NACO/VLT. (image
from Ménard et al. (2005), in prep.). Right panel: 12µm scattered light image of HK Tau B obtained with
KECK/LWS. Image from McCabe et al. (2003)
light at 4µm comes from a layer located twice as close to the ring midplane than the visible scattered light
(see Figure 6.2). Combined with the need for larger grains to account for the scattering phase function in the
thermal infrared, and the need for very small grains at the disk surface to account for the large polarisation
observed (Silber et al. 2000, ApJ, 536, L89), this is the first direct evidence for the stratification of dust grains,
possibly as a result of vertical settling. This settling is a necessary step for dust to accumulate in the disk
midplane and to grow into planetesimals, i.e., to start forming larger bodies, eventually rocky cores of planets,
in the disks.
0.8 µ m 3.8 µ m
1"
Figure 6.2: Left Panel: HST/ACS F814W image of the circumbinary ring of GG Tau (image from Krist et al.
2005, ApJ, in press). Right panel: 3.8uµm scattered light image obtained with KECK. Image from Duchêne
et al. (2004)
To further probe small grains, and whenever possible, polarimetric mapping is also obtained. However, due
to the paucity of polarimetric data, studies have been completed only for a few sources so far. Silber et al.
(2000, ApJ, 536, L89) presented to first polarisation of a disk (GG Tau). Glauser et al. (2005) in prep. are
finalising the analysis for IRAS 04158+2805. Our group is one of the very few using that powerful property of
light for disk studies.
In a parallel approach to scattered light images, we pursue millimeter interferometric images of T Tauri
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E
E
N
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disks. At these wavelength, the bulk of the emission comes from the midplane of the outer disk, a region that is
not probed by scattered light images which are sensitive to grains in the disk surface. By attempting to model
simultaneously the millimeter thermal emission and the scattered light images, we are constraining the vertical
structure of disks and the possible presence of mm-sized particles in the disk midplane. In our first millimeter
study of the edge-on disk around HK Tau B, based on data collected at IRAM’s Plateau de Bure Interferometer,
we have shown that the disk must have layered structure, with a physical disconnection between the midplane
and disk surface in order to explain all observations of that disk (Duchêne et al. 2003).
To complement the various types of images descrived above, we are also involved in the ”Core To Disk”
Spitzer Legacy Survey, from which we hope to construct complete SEDs over the entire infrared range (from 3
to 170µm). Combined with the constraints obtained from the analyses of the disk images, this will allow us to
probe the parts of the disk that are not well sampled by current imaging techniques.
Our efforts in the observation (and models) of protoplanetary disks are well received and lead to several
invitations for review talks at international conferences, including a full review chapter awarded (with Ménard
PI) at the prestigious Protostar & Planets V conference (Hawaii, Oct.2005).
To wrap-up this section, it is our hope that models of numerous protoplanetray disks will help us identify
systematic trends and characterise important physical mechanisms like setlling, or show the presence of asymmetries
and complex dust properties, to understand the processes by which disks evolve, a mid-term goal, and
ultimately form planets, a long term-goal.
The inner dust disk
While the section above dealt mostly with the outer parts of disks, say 30AU and outwards, i.e., the resolution
available with HST and ground based adaptive optics at 150pc, the distance of nearby star forming regions,
other members of team FOST focus their attention on the inner disk by using another high angular resolution
technique, namely infrared interferometry. The goal of these efforts is to investigate the physical conditions in
the disk close to central star and to better understand the different evolution stages of these disks.
To reach these goals, data is obtained from most existing interferometers (PTI, IOTA, VINCI, MIDI). We
have also improved our interpretation capacities by developing a code dealing with the vertical structure of disks
and other radiative transfer tools based lambda iteration and Monte Carlo techniques to extract predictions
from the vertical structure code.
Finally, a part of the team is involved, through GRIL, in the development of new instruments like IONIC
on IOTA and AMBER on the VLTI. Thanks to this instrumental involvement, we have access to a large part
of observing time at IOTA and part of the AMBER guaranteed time but also a privileged access to the VLTI
Science Demonstration Time on objects not observable by the existing instruments.
The staff involved over the period 2001-2005 include Jean-Philippe Berger, Fabien Malbet, Jean-Louis Monin,
together with PhD students Regis Lachaume, Carla Gil, Eric Tatulli, and Myriam Benisty and undergraduate
students F. Millour (Master 2 student) and E. Herwats (Master 2 student).
Models of vertical structure To analyse the interferometric observations our models of the vertical structure
of disks have been improved following the initial work by Malbet & Bertout, 1991, ApJ, 383, 814), as part of
the PhD thesis work of R. Lachaume. Influenced by the approach of Chiang & Goldreich (1997, ApJ, 490, 368),
Lachaume developped a two layer model that provides an adequate analytical solution to the more complex
numerical simulations (Lachaume et al. 2003). This model successfully reproduces the observations of T Tauri
disks: both the SED and the visibilities. It also predicts that in the inner zone where the viscous dissipation
is the main heating source, the flaring angle of the disk surface is driven by the accretion and the opacity
contrarily to the outer disks where it is driven by the direct stellar radition heating. Lachaume et al. (2003)
further showed that at the same radius, the outgoing flux can be dominated by the stellar flux reprocessing
whereas the vertical structure of the central layers are regulated by the accretion rate, see Fig. 6.3.
FU Orionis under scrutiny Malbet & Berger conducted the largest interferometric campaign to date on
the young stellar object FU Orionis, as part of an international collaboration including observations on PTI,
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Figure 6.3: Contribution of heating processes in a T Tauri disk: radial profile of these contributions to the temperature
of the disk. Left: mid-plane temperature, middle: effective temperature, right: surface temperature.
One sees that in the inner 2 AUs the mid-plane temperature is dominated by the viscous dissipation. From
Lachaume et al. (2003).
IOTA and VLTI/VINCI.
Figure 6.4: FU Orionis disk-spot model. Lines corresponds to the best model fit and markers to visibilities in
binned form. Top-left panel: spectral energy distribution and best fit model. The solid line stands for the whole
model and the dashed one for the spot. Right panel: visibility data vs. hour angle for each baseline in H and
K. The contribution of the disk is displayed in dashed lines. Bottom-left panel: synthetic image in logarithmic
scale. East is left and North is up. From Malbet et al. (2005).
FU Ori was observed on 42 nights over a period of 6 years, from 1998 to 2003. 287 independent measurements
of the fringe visibility with 6 different baselines ranging from 20 to 110m, in the H- and K-bands, were obtained,
see Fig. 6.4. Our data resolve FU Ori at the AU scale, and provides new constraints at shorter baselines and
shorter wavelengths. Our extensive (u,v)-plane coverage, coupled with the published spectral energy distribution
data shows that FU Ori hosts an active accretion disk whose temperature law is consistent with standard
models. A 10% peak-to-peak oscillation is detected in the longest baseline data. It is interpreted as a possible
disk hot-spot or companion. Although this bright spot on the surface of the disk could be tracing some thermal
instabilities in the disk, we have proposed to interpret this spot as the signature of a companion of the central FU
Ori system on an extremely eccentric orbit. We speculate that the close encounter of this putative companion
and the central star could be the explanation of the initial photometric rise of the luminosity of this object.
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Wind and disk interaction in MWC 297 The young stellar object MWC 297 is an embedded B1.5Ve
star exhibiting strong hydrogen emission lines and a strong near-infrared continuum excess. This object has
been observed by the AMBER/VLTI instrument on a 45m baseline in a region of the K spectral band centered
around the Brγ line. The object has been resolved in the continuum with a visibility of 0.50 +0.08
−0.10 in the Brγ
line, where the flux is about twice larger than in the continuum, with a visibility about twice smaller 0.33±0.06.
We applied a combined model that includes a geometrically thin accretion disk model consisting of gas and
dust and a stellar wind model. The hydrogen emission, about twice more resolved than the continuum, can be
reproduced by the emission of a latitude-dependent wind model above the disk surface. A picture is emerging
in which MWC 297 is surrounded by an equatorial flat disk, possibly still accreting, and an outflowing wind
which has a much higher velocity in the polar region than at the equator (Malbet et al. 2005, A&A, submitted).
These observations are the first to separate spatially and spectrally the disk radiation and the wind emission
within the inner 1 AU from the central sources. It shows the power of AMBER and many similar sources will
be observed and yield hopefully to a better understanding of the connection between the disk and the wind in
young stellar objects.
6.3.2 The star-disk interaction
The previous section dealt with the parts of the disk located typically at a few AU’s from the star (1-3 AU).
Moving further inward, the dust in the disk sublimates and only gas is left. At one point the disk material
moving inward because of accretion will encounter the top of the stellar magnetosphere. Whether the accretion
flow will keep going “equatorially” to form a boundary layer before reaching the photosphere or be channelled
by the magnetic field depends on the relative balance between “magnetic pressure” and “accretion pressure”.
Magnetospheric accretion, i.e. the magnetic channelling of the accretion flow from the inner disk onto the
star, is now believed to be a central process in young stars in that it regulates their angular momentum during
pre-main sequence evolution, diverts part of the accretion flow into a powerful ionized jet, and possibly halts the
inward migration of proto-Jupiters close to the young star. FOST’s involvement in the study of magnetospheric
accretion is mostly observational. However, to improve our capacity for models and interpretations, a PhD
thesis (N.Bessolaz) has been started jointly with SHERPAS in november 2004.
Magnetospheric accretion
Our work aims at deriving the structure of the magnetospheric cavity, the physical conditions at the inner disk
edge and in magnetic funnel flows (accretion columns), as well as constraining the temporal evolution of the
whole structure. With this goal in mind, we have organised and performed several international campaigns of
observations involving between 10-15 observatories world-wide and an even larger number of collaborators. By
monitoring the spectroscopic, photometric and polarimetric variability of young stars on a timescale of several
weeks, we characterize the dynamical processes (accretion, ejection, magnetic field evolution) involved in the
magnetospheric accretion process (Bouvier et al. 1999, A&A, 439, 619; Bouvier et al. 2003; Ménard et al.
2003).
We thus showed that the observed variations of the photometric and spectral diagnostics (luminosity, line
profiles an intensity, veiling, etc.) were broadly consistent with the magnetospheric accretion concept : all
diagnostics are modulated on a timescale of a week which reflects the rotation of the star and its magnetosphere
up to the inner disk edge. Hence, all accretion signatures (hot spot at the stellar surface, veiling, accretion
columns) vary in phase as the whole magnetospheric accretion structure rotate at the same angular velocity
than the star. The photospheric luminosity is modulated as well, with the same period but anti-phased. This
suggests that the inner disk edge is warped by the stellar magnetosphere as material is lifted up above the
disk plane to be loaded into magnetic funnel flows and thus periodically occults the central star. This further
indicate that the stellar magnetosphere is inclined relative to the stellar rotational (and disk) axis (Bouvier et
al. 2003).
While the observed variability can be broadly accounted for in the framework of the magnetospheric accretion
model, we additionally showed that the variability pattern changes over a timescale of several weeks. This
indicates that the magnetospheric structure itself reacts to the interaction with the disk perhaps in a cyclic-like
fashion, first inflating as the result of differential rotation between the star and the disk, then opening and
reconnecting to eventually return to its initial, roughly dipolar configuration. We have reported evidence for
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such mid-term (several weeks) magnetospheric cycles from the observed modulation of both accretion and wind
diagnostics in long time series of observations (Bouvier et al. 2003).
These results first confirm the validity of the magnetospheric accretion paradigm but also prompt new
developments in the analytical and numerical models. As observations suggest, the magnetically-mediated
accretion process is highly non-axisymmetric and quite time-dependent as a result of the feedback of accretion
flow onto the magnetospheric structure. These refinements are now just being included into the latest numerical
simulations of magnetospheric accretion in young stars (e.g., Romanova et al. 2004, ApJ, 610, 920). These results
have been acknowledged in the community and prompted invitations to give reviews at several international
conferences, the most recent one being a full review chapter awarded on this subject (with Bouvier PI) at the
Protostar & Planets V conference (Hawaii, Oct.2005).
This work, led by our group at LAOG (Bouvier, Dougados), has been made possible through a large number
of collaborations, sometimes funded by official programs (e.g. MAE 2003-2004, Econet 2005-2006), and multiple
visits of collaborators (from 2 weeks up to 1 yr; CNRS, MENRT): K. Grankin and M. Ibrahimov, Uzbekistan;
S. Alencar and J. Vasconcelos, Brazil; J. Muzerolle, USA; C. Clarke, UK.
With a number of stringent observational constraints now at hand, we have embarked into the development
of more realistic MHD models to describe the magnetospheric accretion/ejection process in young stars. Within
a collaborative framework involving both FOST (Bouvier) and SHERPAS (Ferrreira) at LAOG, as well as an
expert MHD group at University Utrecht (Keppens) a joint thesis has been started (N. Bessolaz) in September
2004 on the development of 2D numerical simulations of magnetically-channelled flows. A broader perspective
is also offered by the start of the FP6 RTN JETSET (2005-2008) of which LAOG is a node (Dougados PI) and
which includes the investigation of the magnetospheric accretion process as a possible source of jet outflows.
Finally, we will now attempt the first direct detection of the magnetospheric cavity in young stars through
interferometric measurements with VLTI/AMBER in GTO programs (Dougados, Bouvier, Malbet).
X-rays to probe the star-disk interaction during accretion outbursts
The typical accretion rates in T Tauri stars (10 −7,−8 M⊙/yr) is too weak for accretion pressure to rule over
magnetospheric pressure, forcing the infalling material to proceed along the field lines, i.e., magnetospheric
accretion (see previous section). For higher accretion rates however, the inner rim of the disk moves closer to
the photosphere, possibly reaching the photosphere for extreme accretion rates. A boundary layer results.
Young solar-like stars are thought to experience these phases of extreme accretion (10 −4,−5 M⊙/yr) several
times during their early life. During these accretion bursts, known as FU Orionis and EX Lupi phases, the
luminosity of the object is dominated by the emission of the heated inner disk. In that case, direct study of the
star-disk interaction zone is next to impossible by “classical” methods.
In November 2003, the “anonymous” star V1647 Ori erupted dramatically and produced the rise of the
McNeil’s nebula, discovered serendipitously by amateur astronomer McNeil in Jan. 2004. This outburst is
explained by an increase of the disk accretion rate from 6 × 10 −7 to 10 −5 M⊙ yr −1 . N.Grosso from FOST, in
collaboration with J.Kastner (Rochester Institute of Technology) used Chandra (an american X-ray satellite
observatory) to reveal a factor ∼100 increase in the X-ray flux of this source compared to pre-outburst values.
The coincidence of this surge in X-ray brightness with the optical/infrared outburst demonstrates that strongly
enhanced high energy emission occurs as a consequence of high accretion rates in V1647 Ori (Kastner et al.
2004).
Follow-up observations with XMM-Newton confirmed the high levels of X-ray emission observed with Chandra,
and showed enhanced X-ray variability from V1647 Ori in outburst (Grosso et al. 2005). The observed
variability of the X-ray flux does not appear typical of X-ray flares from other young stellar objects, and could
be produced by the Keplerian rotation of a warped accretion disk. A follow-up project at IRAM has been
started by Grosso in collaboration with team ASTROMOL to characterise the accretion disk of V1647 Ori.
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6.3.3 The physics and origins of mass-loss in T Tauri stars
The physical mechanism by which mass is ejected from accreting systems and collimated into jets is another
fundamental problem in star formation that FOST is interested in. MHD accretion-driven wind models appear
required to explain the efficient collimation and the large ejection to accretion ratio of 0.01-0.1. Two broad
classes of models have been proposed: ejection from the stellar surface, or magnetocentrifugal ejection from
the associated accretion disk. Distinguishing between these scenarii is vital not only for understanding the jet
phenomenon in itself, but also for modelling the formation of exoplanets, as they have distinct implications on
the density structure and the migration processes in the inner regions of protoplanetary disks.
At the T Tauri phase (at ages > 10 6 yrs), most of the residual infalling envelope is evacuated, allowing direct
observation of the inner 100 AUs where ejection models predict that most of the collimation and acceleration
processes occur. Since 1996, C.Dougados and co-workers have been conducting sub-arcsecond observations of
the central regions (a few 100 AUs) of the jets associated with T Tauri stars. These observations are confronted
to detailed predictions from MHD wind models to constrain the jet launching mechanism in these sources.
This work is done in close collaboration with S. Cabrit (LERMA, Obs. de Paris), J. Ferreira (LAOG) and
P. Garcia (University of Porto). A thesis work on this subject was conducted by N.Pesenti (LAOG). These
observational constraints have so far favored a disk wind origin: the increase of jet widths with distance, the
onion-like structure of the DG Tau jet with faster gas nested inside slower material, and the detection of
rotation signatures are all successfully reproduced by MHD wind models with launch radii of 0.1-3 AU. Our
main contributions in the past 4 years are detailed below.
One of the major breakthroughs, in recent years, has been the report of tentative rotation signatures in 4
T Tauri microjets (Bacciotti et al. 2000, ApJ, 537, L49; Woitas et al. 2002, ApJ, 580, 336; Coffey et al. 2004,
Ap&SS, 292, 553). It has been soon recognized that the measure of azimuthal velocities is a powerful tool to
constrain the streamline launching radius (Bacciotti et al. 2002, ApJ, 576, 222). Azimuthal velocities directly
computed from observed velocity shifts indicate launching radii in the range 0.1-3 AU, the strongest indication
to date of a disc wind origin. In his thesis work, Nicolas Pesenti, has shown however that projection and dilution
effects significantly alter the derivation of azimuthal velocities from observed velocity shifts and that a careful
and detailed comparison with model predictions is required (Pesenti et al. 2003). Extending the analytical
work of Anderson et al. (2003), we have also computed predicted azimuthal velocities in the context of X- and
stellar-winds (Ferreira et al. submitted).
In order to fully test the reported rotation detections in T Tauri jets, we have also launched an observational
campaign with the IRAM Plateau de Bure interferometer to map rotation in the associated disk. So far disk
rotation has been checked against jet rotation for only 2 sources and the results are perplexing. While the
DG Tau circumstellar disk appears to rotate in the same direction as reported for the jet (Testi et al. 2002,
A&A, 394, L31), the RW Aur disk does not! (Cabrit et al. A&A submitted). These observations further suggest
that care should be taken in the interpretation of reported T Tauri jet rotation signatures. Further jet sources
will be observed at IRAM/PdBI in the forthcoming years within the JETSET/RTN collaboration.
Exploring jet tracers in the near-infrared domain is critical to analyse current AO observations obtained on
8m-class telescopes and efficiently prepare future observations with AMBER/VLTI (The LAOG is co-I on 2
GTO AMBER/VLTI observations on T Tauri jet sources). Another aspect of Pesenti’s thesis work was therefore
to develop a tool for the prediction of the near-infrared [Fe ii] line emission of wind models. This tool was first
applied to the self-similar disk wind models developped by Ferreira and collaborators from SHERPAS (Pesenti
et al. 2003).
6.3.4 Observations and models of the more evolved “Debris disks”
Debris disks are circumstellar dust disks imaged in scattered light around young main sequence stars (typically
10 Myr or older). Contrary to genuine protoplanetary disks, these environments contain almost no gas and are
optically thin. Their dynamics is therefore mostly gravitational. These disks are interesting because they are
probably young planetary systems that are not fully dynamically relaxed. Their study is then of great interest
for our understanding of the processes that give birth and make evolve planetary systems in general.
The prototype of these disks is the dust disk orbiting the star Beta Pictoris which remained, for many years,
the only one known. In the past 5 years, our group has been involved in the discovery of new debris disk
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systems: HD 141569, HD 32297, HD 181327. Other disks like HR 4796 and AU Mic for example were also
studied by our group. (Augereau et al. 1999, A&A, 348, 557; Boccaletti et al. 2003).
Since debris disks are optically thin, their dust density profiles can be directly extracted from spatially
resolved scattered light images. When available, the colors of the disk (in scattered light) can be related directly
to the size distribution of the smallest dust grains (Boccaletti et al. 2003; Augereau et al. 2004). The situation
is slightly more complex for edge-on disks (Beta Pic, AU Mic, HD32297 for instance) and a specific inversion
procedure was developed in order to reconstruct the dust density from brightness profiles (e.g., Augereau &
Beust, A&A, submitted for AU Mic). These profiles, once included into the debris disk radiative tranfert model
we developped to adjust the SED, give insight on the dust properties (grain size distribution, composition).
The model results serve as inputs for our dynamical modeling of the colliding planetesimals disks that release
the observed dust grains (e.g., Augereau et al. 2001). They are also incorporated into the chemistry model of
the remnant gas disk around HD 141569 that we have detected with the IRAM Interferometer (Augereau et al.
in prep.).
Although the inner regions of most debris disks appear to be largely dust-depleted, the actual amount of
dust is poorly known. Our group is involved in the detection and modeling of a very small amount of dust
in the Vega inner system (within about 1AU) based on CHARA/FLUOR infrared interferometric observations
(Absil et al., submitted). This exo-zodiacal dust population around Vega may be related to collisions among
asteroid-like objects and/or due to evaporating comets.
Beta Pictoris itself has been studied now for years by our group. In the past 4 years, a collaboration has
been initiated with members of the Laboratoire de Planétologie de Grenoble (LPG). The goal was to better
understand the physics of planetesimal evaporation in the vicinity of the star. Indeed, repeated transient changes
in the absorption spectrum of Beta Pictoris had been attributed for years to the sublimation of star-grazing
planetesimals. The goal of the collaboration was to translate models of solar system comets to the case of Beta
Pictoris to better understand the physics of their sublimation and better constrain the model. This constituted
the thesis of C.Karmann under the supervision of H.Beust. The main outcome of the study was that the
planetesimals in the Beta Pic system contain probably very little ice, and that their sublimation rate depends
on their distance to the star but also on their history, with possible seasonal effects (Karmann et al., 2001;
2003).
6.3.5 Dynamical evolution of young circumstellar environments
Our team has also developped a long-term collaboration with the group of John Papaloizou (QMWC and Cambridge,
UK) to model the complex structures of spatially resolved debris disks. The models involve pertubing
planets like in the Beta Pic and Vega disks (Augereau et al. 2001; Reche et al., in prep.) but also the effect
of radiation and wind drag forces on the grains (e.g., AU Mic, Augereau & Beust, submitted). In the case of
Beta Pic, this type of approach has allowed to place an upper limit on the gas mass in the system (Thébault &
Augereau, 2005). Some systems like HR 4796 are not isolated and the effect of stellar companions must be investigated.
In the case of HD 141569 for instance, we show that the large-scaled spiral structure observed likely
results from the secular perturbation of the disk by the two bound M-star companions (Augereau & Papaloizou
2004, see Fig. 6.5). As part of the PhD thesis of R.Reche, we are now exploring the effects of an additional
perturber, a Jupiter-mass planet, on the inner disk structure that remains unexplained.
The grains observed in debris disks arise from mutual collisions between larger particles (up to km-sized
bodies). We have thus started to numerically investigate the outcome of collisions in debris disks to predict the
size distribution as a function of time and distance from the star to see if it could affect the interpretation of
the observations, especially the mid-infrared excesses measured with ISO and Spitzer.
6.3.6 Other Topics in Star Formation
X-ray emission from Young Stellar Objects
Many members FOST are involved in several long exposure observations of star forming region called ‘large
projects’, a highly competitive category of Chandra and XMM-Newton observations. This effort is lead by
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Figure 6.5: Observation and model of the spiral structure in the disk of HD 141569. Left Panel: HST/ACS
optical observations. The image is de-projected to provide a pole-on view of the disk.Middle Panel: Synthetic
image of disk showing the spiral structure caused by the remote companions. Right Panel: Geometry of the
multiple system.
N. Grosso who participates actively in all programmes, together with T.Montmerle (Astromol). Other members
of FOST are actively involved in XEST (Bouvier, Dougados, Ménard, Monin, and PhD student Guieu). The
surveys we participate in are:
• The Chandra Orion Ultradeep Project (COUP) COUP is a nearly continuous observation of the Orion
nebula cluster over about 13. days that took place in Jan. 2003. It yielded an exceptionally deep total onsource
exposure time of about 10 days. A total 13 papers, with 8 co-signed by N.Grosso and T.Montmerle
(ASTROMOL), were published in the October 2005 COUP special issue of The Astrophysical Journal
Supplement.
• The X-ray Emission Survey of the Taurus Molecular Cloud (XEST) This X-ray survey of the Taurus
Molecular Cloud with XMM-Newton was proposed by Manuel Güdel (Paul-Scherrer Institut, Zürich). It
is closely linked to the Taurus optical survey carried by our group at CFHT, and with a Spitzer survey
(PI is D.Padgett, Caltech) of the same zone. Data is currently being analysed for all three surveys.
• The Deep Rho Oph XMM-Newton Observation (DROXO) The dense core F of the ρ Ophiuchi dark cloud
was first studied in X-Rays by H.Ozawa (postdoc from April 2002 to March 2004) with an exposure of
33 ks with XMM-Newton. Ozawa et al. (2005) detected 87 X-ray sources, of whom 25 are new X-ray
sources. DROXO, proposed by Salvatore Sciortino (Palermo observatory), is a ten day long XMM-Newton
observation of roughly the same area to study spectral and variability properties of young stellars objects.
Observations have been performed on March 2005.
Spitzer Legacy surveys: Cores-to-Disks (C2D)
Our team is involved in the Spitzer c2d Legacy program designed to study the evolution of circumstellar matter
’From Molecular Cores to Planet-Forming Disks”. This program utilizes in particular the improved sensitivity
of the Spitzer InfraRed Spectrograph (IRS5, 5-35 micron) to study ices towards low-mass embedded protostars
(Boogert et al., 2004) and toward extincted background stars. The Spitzer/c2d spectra toward a variety of
solar-type PMS stars also greatly expand the study of infrared emission features in solar-mass stars, which
previously were restricted primarily to ground-based studies in the 10 micron window. A large fraction of the
silicates features are weak and flat, consistent with micron-sized grains indicating fast grain growth. In addition,
approximately half of the T Tauri star spectra show crystalline silicate features near 28 and 33microns indicating
significant processing when compared to interstellar grains (Kessler-Silacci, Augereau et al., submitted).
Furthermore, PAH emission is observed towards at least 5 T Tauri stars out of 33, with 11 tentative detections
still to be confirmed, resulting in a lower limit of 15% detection of PAH in T Tauri stars (Geers, Augereau et al.,
in prep). Although PAH features are widely observed, in particular in circumstellar disks around Herbig stars,
there was no consensus before these results on the presence of PAHs in protoplanetary disks around T Tauri
stars and whether or not they were receiving sufficient stellar radiation to produce observable signatures.
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C2D Spitzer/IRAC and MIPS data of star forming regions, coupled with our optical surveys of the same
clouds, are used to study the presence and properties of disks around brown dwarfs and weak-line T Tauri stars.
6.4 Selected topics on the IMF and the properties of low-mass Populations
6.4.1 The low-mass population of nearby Star Forming Regions
The brown dwarf population of the Taurus Molecular cloud
In 2000, we initiated a deep large scale optical survey of the Taurus molecular cloud at CFHT. Today, the
coverage of the cloud is of order of 30% and we have unveiled 17 new brown dwarfs in this low density star
forming region (Guieu et al. 2005, and PhD Thesis). Taking into account the 4 brown dwarfs also discovered
by our group earlier, Martin et al. 2001, we have ∼doubled the number of known substellar objects in this
star forming region. We have studied the spatial distribution of the brown dwarfs in Taurus, and contrarily to
previous claims, we find that there is no brown dwarf deficit in Taurus. The ratio of brown dwarfs to stars in
Taurus is now consistent with other estimations elsewhere, in Orion for example.
We also find that a significant number of brown dwarfs show Hα emission and other signatures of accretion,
indicative of the presence of circumstellar disks. Using our collaboration with the Spitzer C2D legacy team, we
are currently investigating the mid-infrared excess of numerous brown dwarfs in Taurus. These results show
that half of the brown dwarfs in Taurus harbor a significant infrared excess, hence possess a circumstellar disk.
Figure 6.6: Spatial distribution of newly found BD in Taurus (open triangles) and previously known BD (open
circles). Black dots locate Taurus young stars. Image credit: S.Guieu.
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Multiplicity of protostars
Following our investigation of multiple systems among low-mass PMS and ZAMS stars aimed at constraining
the star formation process from the statistics of multiplicity (e.g., Duchêne, 1999, A&A, 341, 547), we have
recently focussed on the earliest stages of star formation by investigating the multiplicity of near-infrared
embedded sources in star forming regions. These embedded sources are the observable objects closest to the
protostellar stage. Duchêne & Bouvier, with Co-I André & Motte (Saclay), and Bontemps (Bordeaux) derived
the fraction of wide binaries among these sources from direct near-IR imaging at CFHT and ESO. An excess of
multiple systems compared to older low-mass stars in the field is found. This new result, for the youngest stellar
objects known, tends to confirm the ubiquity of fragmentation during molecular core collapse, thus leading to
multiple protostars which later decay through dynamical relaxation or are disrupted by gravitational encounters
in dense clusters (Duchêne et al. 2004).
Taking advantage of the unique capabilities of the near-infrared wavefront sensor of the NACO Adaptative
Optics system on VLT, we are now in the process of investigating the tightest of these protostellar systems,
down to a resolution of 10 AU. Preliminary results reveal a number of close systems with separations in this
range, see Fig. 6.7. A complete census of multiple protostellar systems over the range 10-1500 AU awaits the
completion of the VLT NACO runs. Meanwhile, we have started follow up spectroscopy of the faintest and
most embedded companions to protostars, with the aim to search for proto-brown dwarfs. In 2005,we will also
obtain the first VLTI-MIDI mid-infrared interferometric observations of these objects, in an attempt to detect
the tightest embedded multiple systems, thereby setting constraints on the fragmentation scenario for systems
just a few AU appart, and to determine the structure of the dusty envelopes surrounding these protostars.
L1689 IRS 5 (ophiuchus) SVS 20 (Serpens) WL 20 (Ophiuchus)
0.5"
Figure 6.7: Three examples of multiple protostellar systems observed with VLT/NACO. Note the strange
physionomy of the third companion of the WL 20 system, which is not an artefact but most likely an edge-on
disk. Image credit G. Duchêne and J.Bouvier
While our current results indicate a high frequency of multiplicity among protostars indeed, thus supporting
fragmentation during core collapse, we find no evidence for the existence of small-N unstable aggregates (N=5-
10) in the protostellar stage, contrary to what several numerical models of core collapse predict through multiple
fragmentation. This disagreement probably points to the simplified physics included so far in the numerical
models which, for instance, neglect magnetic field, use a poorly constrained equation of state, and do not take
into account feedback effects resulting from the strong wind of young protostars onto the collapsing cloud. Our
results regarding the end products of core collapse in several star forming regions thus provide some guidance
to improve numerical models.
On the nature of Infrared companions to T Tauri stars
Taking advantage of the high-angular resolution imaging and spectroscopic devices available on the VLT and
Keck telescopes, we have been studying for the last few years the nature of the so-called ”infrared companions”
to T Tauri stars. These objects are best exemplified by T Tau Sa, the optically undetectable companion to the
prototype young stellar object T Tau. The spectral energy distribution of these objects would classify them
as embedded, Class I protostars, but their close vicinity (a few tens to hundreds of AU) to more evolved T
Tauri stars suggests otherwise. Using the Keck telescope in collaboration with Andrea Ghez (UCLA), we have
obtained medium resolution near-infrared spectra of two such objects (T Tau Sa and V773 Tau D (Duchêne
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et al. 2002; 2003). We have found that their spectrum is entirely featureless, showing that they are either
intermediate-mass early-type stars seen in scattered light due to heavy obscuration along our line-of-sight by
some dusty circumstellar material or lower mass objects entirely embedded in an optically thick envelope.
In the case of T Tau Sa, we have further obtained a high resolution (R∼30000) near-infrared spectrum that
clearly shows the presence of warm (∼400K) gaseous material on the line-of-sight to the central target; the
absence of kinematical signatures of infall or outflow clearly suggests that the object is an early-type star that
is surrounded by a compact, opaque edge-on disk that has not been spatially resolved so far. More recently,
VLT-NACO observations of another infrared companion system, WL 20 in Rho Ophiuchus (see Fig. 6.7, right
panel), has revealed a complex nebulosity that is most likely seen in scattered light, again suggesting that
the interpretation of these infrared companions in terms of embedded protostars is unlikely to be an adequate
framework.
In the near future, we plan on obtaining additional high angular resolution images in the near- and midinfrared
of these systems, as well as high spectral resolution spectra in order to identify photospheric features
and/or gaseous material located along our line of sight to these objects.
Binary stars and dynamical masses
The mass of a star is probably its most fundamental property. It is however extremely difficult to measure
directly and one usually relies on models (or mass-luminosity relations) to get an estimation. Of concern for
us, pre-main sequence evolutionary models are subject to significant uncertainties related to the complexity of
the various relevant physical processes. It is therefore necessary to determine model-independent masses for T
Tauri stars in order to calibrate the theoretical evolutionary tracks, in particular towards the low-mass end, as
masses for very low-mass stars and brown dwarfs are then used in other studies, such as that of the initial mass
function in star-forming regions.
Using speckle interferometric observations of young tight binary systems at Keck in collaboration with
Andrea Ghez (UCLA), we have monitored several tight T Tauri binary systems in order to determine the
orbital parameters and, eventually, the masses of these objects. Dynamical masses for several systems were
obtained (V773 Tau (Duchêne et al. 2003); DF Tau, TWA 5) with typical accuracies of 10-20%, where the
uncertainty in the distance to the system dominates the uncertainties in the Keplerian orbital fit. We have also
applied the same technique to the orbit of a field star-brown dwarf system, 2MASS0746425+2000321 (Bouy et
al. 2004), for which an accuracy of 5% was reached, this time helping to calibrate the relations valid for the
lower-main sequence.
As part of the AMBER consortium, we have obtained Guaranteed Observation Time to conduct the same
type of project on much tighter (

masses up to 10 solar masses for a number of clusters and found that the mass distribution over this range can
be described by a single lognormal functional form. Second, we showed that the cluster’s MF is invariant, i.e.,
the same for all the regions we studied, which suggest that the mass distribution of stars and brown dwarfs does
not depend much on environmental conditions at the epoch of formation. These results are now reasonably
accounted for by new models of star (and brown dwarf) formation which rely on the fragmentation of molecular
clouds resulting from MHD supersonic turbulence.
Star formation models also predict a minimum mass for fragmentation of order of 3-8 Jupiter masses. Hence,
the Initial Mass Function (IMF) is expected to have a lower limit at this scale. While the sensitivity of the
optical surveys we have performed so far reached about 30 Jupiter masses, the advent of infrared mosaic cameras
will now allow us to detect brown dwarfs in young clusters down to a few Jupiter masses. We have therefore
submitted a new large program at CFHT using WIRCAM, built in part at LAOG, in order to probe the low
mass end of the mass function of young clusters, in the range from a few to 30 Jupiter masses. If granted,
the surveys will start in 2006 and last for several semesters, thus completing our current results obtained from
optical surveys (CFHT 12K, MEGACAM) and providing new clues to the formation and dynamical evolution
of free-floating planetary mass objects in young clusters.
As most of the collaborators involved in the optical surveys over the last few years will also participate to
the new IR surveys (Cambridge, Arcetri, Potsdam, Cardiff, Kiel, Madrid, Canarias, Caltech, CFHT), we very
recently applied for another FP6 RTN which will focus, at least in part, on the investigation of the extremes
(upper and lower ends) of the IMF.
In parallel, we have embarked in the modelling of the dynamical evolution of the lowest mass populations of
star forming regions and young open clusters. Preliminary results obtained from numerical simulations using Nbody
codes (Moraux & Clarke 2005; Kroupa et al. 2003) suggest that the various competing scenarios of brown
dwarf formation (collapse, ejection, etc.) may yield distinct cinematical signatures at young ages. Additional
numerical simulations using the most recent N-body codes (in collaboration with Aarseth, Cambridge) will
refine the predicted dynamical evolution of young brown dwarfs in clusters, which we shall then be able to
confront to the results of our CFHT large program.
6.4.3 The low-mass population of the solar neighbourhood
The multiplicity of M dwarfs
With the goals of measuring very accurate dynamical masses and estimating the multiplicity fraction of the very
low mass stars, we carried large programmes on nearby M-dwarfs. These programmes are needed to constrain
star formation theories (multiplicity) and stellar physics (evolutionary tracks, mass-luminosity relations). By
doing so, we uncovered more than 20 new companions (Beuzit et al. 2003; Forveille et al. 2004; 2005).
Multiplicity properties are fairly well known for solar type stars (Duquennoy & Mayor 1991, A&A, 248,
485; Halbwachs et al. 2003, A&A, 397, 159), but it is not the case for the lower main sequence. To date no
determination of the orbital element distribution for M-dwarf binaries has been published. However, multiplicity
fractions ranging from 25% (Leinert et al. 1997, A&A, 325, 159) to 42% (Fischer & Marcy 1992, ApJ, 396, 178)
have been announced.
Our combination of radial velocity and adaptive optics imaging on M dwarfs is the most complete survey
to date for stellar companions in the solar neighbourhood. Our results (Marchal et al. 2003; Marchal et al.
2005 in prep) combined with those of Hinz et al. (2002, AJ, 123, 2027) for very wide binaries enabled us to
derive the multiplicity of M dwarfs. The main results are: (1) a stellar multiplicity rate of 26 ± 3%; (2) M- and
G-dwarfs have very similar separation distributions for separations under 10 a.u. (see Fig. 6.8), (3) at wider
separations M dwarfs have a large companion deficit relative to G dwarfs (see Fig. 6.8), (4) for both M- and
G-dwarfs, the mass ratio distribution is a function of period, (5) similarly to G dwarfs, brown dwarfs are very
rare within ∼100 a.u. of M dwarfs (the “so-called” brown dwarf desert).
These results favor a scenario where the G and M dwarfs form with identical multiplicity properties. The
deficit of M dwarfs at large separations being due to preferential breakup of the looser sytems via dynamical
interactions and orbital decay in compact cluster (Sterzik & Durisen 1998, A&A, 339, 95). The contrasting mass
ratio distributions at small and large orbital separations suggest that two distinct formation modes operate,
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Figure 6.8: Distribution of separations for multiple M-dwarfs of the Solar neighbourhood, compared with the
distribution of solar-type multiples.
one that produces a flat mass ratio distribution over a broad period range, and a second that only forms short
period binaries with nearly equal masses.
The multiplicity of L dwarfs
Where do free-floating brown dwarfs come from? Are they ejected stellar embryos (Reipurth & Clarke 2001, AJ,
122, 432), or do they form like “isolated” stars, by fragmentation of molecular cores? Searching for companions
around L dwarfs is the logical next step to get a complete view of multiplicity accross the mass spectrum and
answer these questions.
To search for companions to L dwarfs, a part of the DENIS sample of ultracool dwarfs (Delfosse et al. 2003)
was observed with HST/WFPC2 (Bouy et al. 2003). 15 new ultracool binaries are reported and statistical
elements determined. The observed frequency of ultracool binaries is lower than that of binaries with G-type
primaries in the separation range from 0.42 AU to 80 AU. There is also a clear deficit of ultracool binaries
with separations wider than 15 AU and a tendency for the ultracool binaries to have mass ratios near unity.
Noteworthy, this astrometric work lead to the first determination of the orbit and dynamical masses of a binary
brown dwarfs: the L dwarf 2MASSW J0746425+2000321 (Bouy et al. 2004), mentioned before in this report.
The deficit of wide ultracool dwarfs binaries reported above by Bouy et al. (2003), but also in Close et al.
(2003, ApJ, 598, 1265) and Gizis et al. (2003, AJ, 125, 3302), is frequently presented as an argument in favour
of the embryo-ejection scenario for the formation of brown dwarfs. To test this scenario, we obtained infrared
images of a very large sample of ultracool dwarfs (250 DENIS late-M and L dwarfs) to detect companion at
separation larger than 1arcsec. We detected the first wide binary for this range of mass (Billères et al. 2005,
see Fig. 6.9), which is clearly not formed by the embryo-ejection scenario. One consequence of this discovery is
that, although rare, low-mass pairs exist and brown dwarfs do not form solely by embryo ejection.
Surveys for field brown dwarfs
For the last 10 years we have used the DENIS survey to find very-late M- and L-dwarfs in the solar neighbourhood
(see for example Crifo et al. 2005; Kendall et al. 2004; Phan-Bao et al. 2003; and Delfosse et al. 2003 for
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Figure 6.9: Top panels: DENIS discovery images of D0551 in I- and J-band. In J-band the object is well
visible with a magnitude J=15.3. Bottom Panels: SOFI images, with better resolution, revealing the binarity
of D0551.
the latest results). A large sample of 300 very late M- and L-dwarfs, identified over 5700 square degrees(!) of
DENIS data, resulted. The sample is complete for objects redder than I-J=3.0 (M8) and brighter than I=18,
and thus statistically well defined. It is an excellent basis for studies of the Galactic disk population of very
low mass stars and brown dwarfs, allowing clean determinations of the luminosity function, mass function, and
multiplicity fraction.
Recently, we extended our study by including the CFHT-Legacy Survey data, with three main goals in mind:
find ultracool brown dwarfs (T

with only three known to date. Most mass determinations for Very Low Mass Stars (VLMS) are therefore instead
obtained from visual and interferometric pairs, which until recently, have not yielded comparable precisions on
mass estimates. By combining very accurate radial velocities with precise angular separations from adaptive
optics, our team reached accuracies of only 1-3% for VLMS (Forveille et al. 1999; Delfosse et al. 1999b;
Ségransan et al. 2000; 2003). To date, masses were determined for ∼30 M dwarfs with accuracies ranging
between 0.5 and 5% by us, with additional measurements becoming available as the time span of our surveys
catches up with longer period systems.
As predicted by stellar structure models, the metallicity dispersion of the field population induces a large
scatter around the mean V-band relation, while the infrared relations are much tighter.
Figure 6.10: V-band Mass-Metalllicity-Luminosity relation. The red filled circles represent our metallicity
determinations and the blue open circles those from WW05. The symbol size is proportional to the metallicity,
and the dashed contours represent iso-metallicity for our calibration, spaced by 0.25 dex from +0.25 (left) to
-1.75 dex (right). The solid lines are the V-band empirical M/L relation of Delfosse et al. 2000.
In Delfosse et al. (2000) it was suggested that metallicity might explain most of this intrinsic dispersion
on the visible mass-luminosity relation, but for lack of quantitative metallicity estimates we could not pursue
this suggestion further. Recently (Bonfils et al. 2005, in press) determined the metallicities for 20 M-dwarfs in
wide-binary systems that also contain an F-, G- or K-star, under the simple assumption that the two stars have
the same composition. We used this data to derive a photometric calibration of the metallicities of very lowmass
stars. The calibration is valid between 0.8 and 0.1 M⊙, needs V- and K-band photometry and an accurate
parallax, and provides metallicity estimates with ∼0.2 dex uncertainties. We use these new metallicity estimates
to take a fresh look at the V-band mass-luminosity relation, and demonstrate that its intrinsic dispersion is
indeed due to metallicity. The first mass-metallicity-luminosity relation for M dwarfs is hence determined (see
Fig. 6.10).
6.5 Selected topics on Extra-Solar Planets
About 150 planetary system have to date been unveiled around stars other than our Sun. They were initially
searched for, and found, around solar-type stars (e.g., Mayor & Queloz 1995, Nature 378, 355; Marcy G.W. &
Butler R.P., ARAA, 36, 57). As a result of this bias, only a few planets around stars with very different masses
are known.
One major motivation to look for planets around “non solar-like stars” is to constrain the planet formation
96

process by comparing its outcome for solar-type stars and for stars of much lower (or larger) mass than the
Sun. Are planetary systems as frequent or not? Do their orbital and mass distributions differ? The answer to
these questions is at present totally unknown.
Surveys for planets around very low mass stars and massive stars are difficult because very low mass stars
are faint, making the measurement of accurate radial velocities expensive in telescope. On the other hand,
massive stars combine high rotational velocities and a small number of photospheric lines, making accurate
spectroscopy a challenge.
In our group, because of the long time collaborations we have been maintaining with the Geneva observatory,
in particular with its exoplanet group, we have been involved early on in radial velocity surveys for planets
around solar-type stars. This was a natural follow-up to the astrometry programmes that had been going-on
for solar-type and low mass stars (led in particular by C.Perrier). This section of our activities is not described
in details here. Instead, we focus on the more challenging planet hunts around low-mass and high mass stars.
6.5.1 Search for planets around very low mass stars
In 2003 members of FOST integrated the HARPS consortium with the duty to pilot the search for planets
around M-dwarfs (Delfosse is PI). 10% of the Harps Guaranteed Time goes to this program (10 nights/yr
during 5 years). The accuracy of the radial velocities reached by HARPS on very low mass stars is between 1 to
3 m.s −1 and semi-amplitudes of 10 m.s −1 are detectable easily. They correspond to planets of 6 Earth masses
in 3-day orbits around a 0.15M⊙ star (13 Earth masses for a 0.6 M⊙ star), or 40 Earth mass planets for a 1000d
period around a 0.15M⊙ stars (100 Earth mass around a 0.6 M⊙ star).
Bonfils et al. (2005b) reported the discovery of a Neptune-mass planet around Gl 581 (M3V). The planet
has a circular orbit of P = 5.366 days (see Fig. 6.11). The minimum mass of the planet (m2 sin i) is only
0.052 MJup = 0.97 MNep = 16.6 MEarth making Gl 581b one of the lightest extra-solar planet known to date.
The Gl 581 planetary system is only the third centered on an M dwarf, joining the Gl 876 three-planet system
(Delfosse et al. 1998, A&A, 338, L67) and the lone planet around Gl 436 (Butler et al. 2004, ApJ, 617, 580).
Its discovery reinforces the emerging tendency for such planets to be of low mass, and found at short orbital
periods.
Figure 6.11: Upper panel: Phased radial velocities for Gl 581. Lower panel: Residuals around the fitted solution
versus time. The weighted RMS of the residuals around the fit is only 2.5 m s −1 . ¿From Bonfils et al. (2005).
In 2006 we plan to start a large program of radial velocity measurements with SOPHIE, the new spectrograph
of the OHP-1.93m telescope. An accuracy of ∼ 3m.s −1 is expected. With both programs, our sample will reach
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300 objects, a size sufficient for statistical studies.
Notwithstanding the caveats raised in the beginning of this section regarding the cost of measuring accurate
radial velocity for faint M-dwarfs, this type of stars remains extremely interesting for future planet search
programmes, in particular when potent imagers will come on-line, like ESO’s Planet Finder. Indeed, M dwarfs
are by far the most abundant objects in the Solar neighbourhood, with 100 of the 120 nearest stars being
M dwarfs. Their proximity makes them very favourable targets for astrometric searches. Similarly, planetary
system around M dwarfs are ideal targets for astrometric measurement of the reflex motion: the very low mass
of the star results in a more favourable mass ratio, and, again, the (statistically) smaller distance produces a
larger angular motion for a given linear displacement. We very recently obtained the first astrometric mass
determination of a planet (Benedict, McArthur, Forveille, Delfosse et al. 2002) around Gl 876. Needless to say,
the planets discovered by the present program will be ideal targets for the PRIMA instrument of the VLTI, if
a suitable reference can be found, as well as for the space astrometry missions. Finally, the brightness contrast
between an M-star and a Jupiter-like planet is very favourable in the infrared for a planet imaging campaign
like the one envisaged with ESO’s PLANET FINDER instrument.
6.5.2 Search for planets around F- and A-stars
The massive Main Sequence stars (spectral type earlier than F8V) have not been investigated for planets until
recently because exhibit a low number of stellar lines (typically a few dozens to a few hundreds for A-F type
stars versus a few thousands for Solar-type stars), and these lines are generally broadened by high rotational
velocities (typically 20-200 km/s versus a few km/s). However, knowing about the presence of planets or brown
dwarfs around more massive objects is also of importance. We already know that the disks around these massive
stars and Solar-type stars are different in terms of properties at similar ages: indeed T Tauri disks aged a few
Myrs appear to be less evolved than those around massive stars aged also a few Myrs such as HD 141569 or
HR 4796, which tend to show that these disks, as the parent stars, evolve more rapidly (Lagrange and Augereau,
2004). The occurence and time scale of planet formation have to be investigated and compared similarly.
Figure 6.12: ELODIE radial velocity data and orbital solutions for a F6V star showing periodic radial velocity
variations corresponding to the presence of a 9.1 MJup planet orbiting at 1.1 AU (period of 388 days). The
eccentricity is 0.34. Top: Radial velocities. Bottom: Residuals to the fitted orbital solution.
The way to process the data and extract the information on radial velocity variations on lower mass stars is
not straightforwardly applicable to more massive stars (Griffin et al, 2000, A&A Suppl. Ser., 147, 299-321). We
introduced (Chelli, 2000, A&A, 358, L59) a new radial velocity measurement method, consisting in correlating,
for a given star and in the Fourier space, each spectrum and a reference spectrum built by summing up all the
spectra, which are specific of the considered star.
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With this new tool at hands, searches for low mass companions around A-F type stars are performed since
2003, in a collaboration between the LAOG and Geneva Observatory teams: radial velocity observations are
obtained with ELODIE (Northern hemisphere) and HARPS (Southern hemisphere). Studies based on such
observations lead to the conclusion that this new RV measurement method can be applied to A-F type stars in
the frame of planet/BD searches (Galland et al., 2005a, A&A, submitted): with ELODIE, the planetary domain
can be reached for A type Main-Sequence stars with v sin i up to 100 km/s and orbital periods less than 10
days. For late A type stars, the accessible range is v sin i up to 80 km/s and orbital periods up to 100 days.
Planetary masses can be detected for all F type Main-Sequence stars. With HARPS, RV uncertainties are lower
(by a factor of 5 to 7), and the planetary domain is accessible for all A and F type stars, even with large v sin i.
100 stars have now been observed with ELODIE at least twice, and 65 at least four times, leading to the
detection of RV variations in 17 cases. Seven of them have a probable planetary origin. A first planet, around
an F6V star has already been characterized (Galland et al., 2005b, A&A, submitted), see Fig. 6.12.
Complementary adaptive optics imaging observations of the same sample has been started with PUE’O at
CFHT (Northern hemisphere), in order to search for companions with large periods, and to test the correlation
between binarity and the presence and properties of planets found by radial velocity.
In 2006, we plan to increase (up to 300 objects) the size of our A-F Main Sequence stars sample for radial
velocity observations with SOPHIE. The sample of stars observed with HARPS will also be increased to 300
objects.
6.5.3 Low-mass companions and planets in nearby associations
The field of extrasolar planet detection and characterization has been limited, so far, to the domain of indirect
detection measurements, either by radial velocity or photometric transit surveys. However, this exploration is
presently intrinsically limited to the close circumstellar environment, typically within ∼4 AU of the central star.
With the development of high contrast and high angular resolution instrumentation, the situation is changing
and the exploration of planets with large semi-major axes becomes achievable.
Figure 6.13: Offset positions in terms of separation (Top) and position angle (Bottom) of 2M1207 b from A,
on 27 April 2004, 5 February 2005 and 31 March 2005 (full circles with uncertainties). The expected variation
of offset positions, if b is a background object, is shown (solid line), based on a distance of 70 pc, a proper
motion of (µα, µδ) = (−78, −24) mas yr-1 for A and the initial offset position of b from A. Also reported are the
associated uncertainties (shaded region) and the different contributions (distance, proper motion, initial offset
position) in dotted lines.
Young and nearby open clusters are ideal targets for such programmes since lower mass objects such as
brown dwarfs and giant planets are brighter when they are young and can thus be more easily detected. It is
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therefore no surprise that vast efforts were made to discover new nearby associations in recent years. Today,
seven nearby associations, open clusters, or so-called ”groups” are known, that are closer than 100 pc from the
Sun with ages of ∼ 10 Myr, or less. We have conducted adaptive optics surveys of several of these associations
in the past 5 years, using the ADONIS, PUEO and NAOS adaptive optics systems.
Figure 6.14: K-band coronagraphic image of AB Pic A and b obtained on 17 March 2003. The diameter of the
occulting mask is 1.4”.
In the course of this on-going deep imaging survey of young, nearby southern associations (Chauvin et
al. 2003), we used the ESO VLT telescope and its adaptive optics near-infrared instrument NACO to image
the close vicinity of the source 2MASSWJ 1207334-393254 (hereafter 2M1207). This brown dwarf 2M1207
was identified by Gizis (2002, ApJ, 575, 484) as a member of the young (8 Myr) TW Hydrae Association
(TWA), a result corroborated later by measurements at optical, infrared, and X-ray wavelengths. In the close
circumstellar environment of 2M1207 A, we discovered a faint planetary mass companion candidate in April
2004 (Chauvin et al. 2004), at ∼780 mas (55 AU). See the discovery image on the cover page of the current
(FOST) chapter. Subsequent observations of 2M1207 A and b, obtained in August 2004 by Schneider et al.
(2004, A&AS, 205, 1114) using the Hubble Space Telescope (HST) and on February and March 2005 with
NACO by our team, clearly demonstrate that the two objects are comoving (Fig. 6.13). They enable us to
reasonably confirm the status of a planetary mass companion to the brown dwarf 2M1207 A. Photometry and
spectroscopy are consistent with a spectral type L5-L9.5 for the companion. Based on H, K and L’ photometry
and evolutionary models, for an age of 8 +4
−3 Myr, we found 2M1207b to lie within the planetary regime, i.e., a
mass of M = 5 ± 2 MJup and an effective temperature of Teff = 1250 ± 200K.
As part of the same deep imaging survey of young nearby associations, we also obtained a direct image
(Fig. 6.14) of a 13—14 MJup companion, assuming an age of ∼30 Myr, at 250 AU of the star AB Pic, a member
of the large Tucana-Horologium association (Chauvin et al. 2005).
These detections provide the first images of planetary mass companions in systems other than our own. It
is very unlikely that these giant planets formed within a circumstellar disk, but more probably via one of two
formation mechanisms proposed for brown dwarfs. These discoveries offer proofs that such mechanisms can
form bodies down to the planetary masses and open new perspectives for our understanding of chemical and
physical properties of planetary mass objects as well as their formtion mechanisms.
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Chapter 7
Future Research Directions
7.1 Research Plans
Over the last few years, since the creation of FOST in 2003, we have progressively refocussed our activities
by including the unifying long-term goal of ”planet formation” to our present goal of understanding ”star
formation”. Recall that the acronym FOST stands for ”Star and Planet Formation” in its contracted form.
Because such a re-orientation takes time and must be smooth to maintain a good coherence within a larger
team, not everyone in FOST works directly on ”planet formation” today. We are convinced this is the right
way because we foresee that our broad range of expertise will lead to innovative breakthroughs in the long run,
breakthroughs that would otherwise have been missed.
Indeed, because of the richness of the scientific background in FOST, we are considering the problem from a
number of independent and interesting directions: be it from the direct search for planets around main sequence
stars and in younger star forming regions, be it the study of proto-planetary disks where planets are thought
to form, or be it the impact of mass-loss on the disk structure, possibly changing the conditions for planet
formation and migration, for example.
This shift in perspective for FOST is rather new. As a consequence, our work should largely keep going
in the current directions for the next few years, i.e., largely into the 2007-2010 period we are considering
here. Therefore, a large fraction of our forecasted activities has been described in the previous chapter. It is
nevertheless useful to recall a few directions we are engaged in and to raise a few questions that will, undoubtedly,
drive our research in the longer term.
In the field of Star Formation We plan to take advantage of JETSET (starting fall 2005) to make advances
in the 2D and 3D numerical simulations of the magnetically mediated star-disk interaction zone (in relation
with SHERPAS). The goal is to confront realistic models with our observations. On the observational side, our
involvement in programmes using 2 powerful spectropolarimeters, ESPADONS at CFHT and NARVAL at TBL
(soon), should allow us to obtain the first, and long awaited for, maps of the magnetic field in this zone. Today
this field is assumed dipolar, but just how close to reality is this hypothesis? The use of X-rays to probe that
zone is original and we will benefit also from the rare expertise we have in this field.
Clearly, the scientific exploitation of AMBER, NACO, and WIRCAM is also at the center of our activities.
The expected returns from these new instruments has been described before, but WIRCAM should allow us
to identify planet-mass objects in nearby star forming regions and estimate the shape of the IMF down to a
few Jupiter masses only, a key piece of information to constrain the star formation mechanisms. NAOS and
AMBER will be extensively used to map disk, from their inner parts (AMBER) to signatures of large scale
asymmetries (NACO), possibly tracing planets. The interpretation of these observations will require continued
efforts to improve our disk models and radiative transfer tools. The need for dynamical models is expected to
increase with time, together with the quality of data available from these instruments.
A long term target for these studies is the preparation for Herschel and ALMA that will provide the necessary
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data to verify the predictions we are making today regarding the structure and evolution of protoplanetary disks
(e.g., dust settling, grain growth, planetesimal formation). PLANET FINDER and VITRUV will complete these
data sets and models by providing images with unprecedented resolution and contrast.
One aspect of our activities that will be new is the study of mineralogy in disks. With instruments like NACO,
VISIR, and SPITZER, we expect to improve our knowledge of the dust properties in disks (size, composition).
This is needed to remove the usual assumption that grains are ISM-like and spherical in disks...
In the field of IMF and low-mass stars we will push further our studies of the substellar populations
by looking for planet-mass objects with large surveys like UKIDSS and the WIRCAM Key project we have
proposed. In the Galactic field, the CFHT-LS will be exploited (and completed by programmes led by FOST
members) to look for the coolest objects, the T-dwarfs and the ammonia-dwarfs (or Y-dwarfs).
In parallel with statistical studies, we consider it important to start studying the individual properties
of these poorly known objects. Masses, metallicities, effective temperatures, etc., will be gathered. Their
atmospheres will be probed by polarimetry (already started, e.g., Ménard et al. 2002) and spectroscopy. We
do no have the expertise yet for the interpretation of planetary atmospheres. Filling that gap is a priority.
In the field of Extra-Solar planets the search for extremely low-mass companions will continue and their
characterisation will ramp up in our work load. With the current instrumentation, these companions offer pretty
much our only chance to detect direct photons from a planet-mass object external to our Solar system. Much
has to be learnt.
HARPS on the ESO 3.60m and soon SOPHIE at OHP will also improve our sample of planets around M
and A dwarfs to a point where statistical studies and follow-ups will become possible. We expect to play a
leading role in both aspects. Both programmes are very recent. They were described in our activity report and
will be carried on for most of the period covered by the present research plan.
To characterise the exo-planets, interferometry will play a large role in our future programmes. It will be
used to derive astrometric masses for numerous objects (with PRIMA for example).
7.2 Needs in personnel
The range of expertise within FOST is broad. New results, often at the very forefront of competitive fields,
are obtained regularly by FOST and progress is being made rapidly. It is therefore difficult, at the present
time, to know exactly what our needs will be terms of personnel in the years to come. Still, a few “profiles”
are emerging, involving specific expertise, that would fulfill forecasted needs in FOST. But by no means should
these few “profiles” be considered definitive or restrictive. Actually, there is much to bet that new needs will
emerge as we make progress, as is normal in science.
It is easy to imagine that very specific competences to deal with continuum radiative transfer (for Herschel
& ALMA) coupled with PLANET FINDER and VITRUV might become needed. Similarly, the latter two
instruments might trigger the need for a data reduction specialist in high contrast, high resolution imaging to
favor full scientific return. On the other hand, dealing with extremely large databases (like those involved in
our current surveys) also requires very specific competences that might become critical a few years down the
road. So clearly, new needs will emerge that we cannot predict today.
Nevertheless, a few profiles can be identified today that would fulfill needs within FOST. They should be
seen as a starting point for our list of requirements in personnel.
• Detection of exoplanets and statistical properties (urgent: 2007-2008)
The French planet hunters have access to the best instruments to measure radial velocities (e.g., SOPHIE
& HARPS). These efficient spectrographs allow to study large samples. Statistical properties can be
derived and planet formation theories tested. LAOG is leading the search for planets around M- and
A-dwarfs in Europe. The analysis work is done as part of two PhD thesis currently under way in FOST
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at LAOG (in collaboration with Geneva Obs.). This chapter of our activities is understaffed and there is
a pressing need for manpower to maintain our position in the current consortia.
• Radiative transfer in emission lines, interpretation of spectroscopic data (mid-term: 2008-2009)
To follow-up on broad-band continuum observations of disks, on low-resolution spectral classification spectra
of brown dwarfs, or to estimate the physical conditions in ionised atomic jets and accretion columns,
FOST is becoming more and more involved in low, mid- and high spectral resolution observations. However,
no one currently at LAOG as the expertise to deal with radiative transfer in lines. It is important to
fill that void in FOST if we are to push further our understanding of the mechanisms linking accretion and
ejection, and more specifically to elucidate the links between the inner disk and the mass-loss phenomenon
where data is becoming available rapidly with AMBER.
• Dynamical models of (proto-)planetary disks (mid-term:2008-2009)
Today, LAOG has access to powerful (symplectic) codes able to calculate the dynamics of dust disks, without
gas, or follow the gas disk, but without dust. The advances permitted by such codes are tremendous,
but it is absolutely clear that disks around young stars are made of gas and dust and both are important:
gas controls the dynamics, dust controls the temperature equilibrium, roughly speaking. In order to look
for traces of planets, to understand the dynamics of disks, and ultimately their evolution, FOST needs
to develop new numerical tools able to deal simultaneously with the gas and dust components of disks.
These codes must be fast and stable to follow the evolution over a long time span. Furthermore, these
codes must be coupled to radiative transfer tools in order to compare with the observations. This is an
extremely complex problem but tentative solutions have been imagined and an international collaboration
has been started to develop such new tools. FOST, currently leading the programme, is understaffed
(because of teaching load) to develop these new tools and help is needed.
• Physical characterisation of Exoplanets (long term: 2009-2010)
LAOG is PI in two major projects for future instruments that will allow to study the physics of extrasolar
planets: Planet Finder (a second generation AO system for the VLT telescope), and VITRUV (a
second generation, multi telescope recombiner for VLTI). These instruments are expected to provide direct
images and low-resolution spectroscopy of exoplanets. Today, the expertise to exploit these data sets does
not exist at LAOG. Acquiring this expertise in complex data reduction and in planetary physics is a top
long-term priority for FOST and for LAOG.
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Chapter 8
Appendices
8.1 Members of FOST
8.1.1 Permanent staff
— Jean-Charles Augereau (CNAP AA)
— Françoise Beck (UJF MdC)
— Jean-Philippe Berger (CNAP AA)
— Hervé Beust (CNAP AA)
— Jean-Luc Beuzit (CNRS CR1)
— Jérôme Bouvier (CNRS DR2)
— Almas Chalabaev (CNRS CR1)
— Alain Chelli (CNAP A)
— Xavier Delfosse (CNAP AA)
— Catherine Dougados (CNRS CR1)
— Gaspard Duchêne (CNAP AA)
— Gilles Duvert (CNAP A)
— Thierry Forveille (CNAP A, on leave at CFHT)
— Nicolas Grosso (CNRS CR1)
— Anne-Marie Lagrange (CNRS DR1)
— Fabien Malbet (CNRS CR1)
— François Ménard (CNRS CR1)
— Jean-Louis Monin (UJF Pr)
— Estelle Moraux (UJF MdC)
— Christian Perrier (CNAP A)
8.1.2 Post-docs
— David James: (EC-RTN FP5)
— Claudio Zanni: (JETSET, joint w/SHERPAS)
— Tim Kendall: (Ministry of Education)
— Willem Jan De Wit: (CNRS fellowship)
— Hideki Ozawa: (Society for the Promotion of Science, Overseas Research Fellowship, Japan, and CNAP)
— Sylvia Alencar: (Brasilian fellowship)
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8.1.3 Graduate Students
Completed PhD’s
— [2002]: Regis Lachaume. [2002-2005]: Postdoc in Bonn, Germany; [2005-2007]: Postdoc in Morelia, Mexico
— [2003]: Estelle Moraux. [2005] hired as assistant professor UJF
— [2003]: Gaël Chauvin. [2003-2005]: Postdoc at ESO, Chile.
— [2004]: Hervé Bouy.[2004-2005]: Post-doc IAC, Spain; [2006-2007]: UC Berkeley
— [2004]: Lydie Marchal. [2005-...]: High school physics teacher
— [2004]: Eric Tatulli. [2005-...]: Postdoc Arcetri, Italy
Ongoing PhD’s
— Vanessa Agra Amboage: (FP6 RTN JETSET grant)
— Myriam Benisty: (jointly w/ GRIL)
— Nicolas Bessolaz: (jointly w/ SHERPAS)
— Xavier Bonfils:
— Philippe Delorme:
— Franck Galland:
— Carla Gil: (jointly w/ ESO)
— Sylvain Guieu:
— Emilie Herwats: (on Belgian grant)
— Guillaume Montagnier: (jointly w/ GRIL)
— Nicolas Pesenti:
— Christophe Pinte:
— Remi Reche:
— Gustavo Rojas: (jointly w/ Sao Paolo University)
8.2 Awards and Prizes
Jérôme Bouvier – The Paul Doistau-Emile Blutet prize from the French Académie des Sciences was awarded
to Jérôme Bouvier in 2002 for his important contribution in the discovery of brown dwarfs in open clusters and
measurement of the lower IMF.
Anne-Marie Lagrange – The Cino Del Duca prize from the French Académie des Sciences was awarded to
Anne-Marie Lagrange in 2005 for her leading role in the search and detection of Exoplanets in France.
Fabien Malbet – The compaq prize (awarded under the auspices of “La Société Française d’Astronomie et
d’Astrophysique (SF2A)) was awarded to Fabien Malbet in 2003 for his pionneering contribution in long-baseline
near-infrared interferometry applied to the study of young stars.
Jean-Louis Monin – Jean-Louis Monin was nominated a Junior Member of the Institut Universitaire de
France (IUF) from 1997 to 2003 (nominal 5 years, interrupted 2 years when he was a scientific director at the
French ministry of research).
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106

Part V
TEAM GRIL
The first fringes of AMBER on the VLTI auxiliary telescopes
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Chapter 9
Presentation of the team
9.1 Foundation
In the early 90’s, because of the local context and a strong political will at the local, regional and national levels,
boosted by the increasing success of IRAM (whose activities LAOG was intended to back at its creation), the
LAOG has built a capacity to get strongly involved in instrumental work for interferometry: research and development
on one hand, with tight interaction with physics laboratories and industry, realization of instruments
for large equipments, with ESO VLTI at the first place on the other hand. It was then specifically oriented
toward interferometry instrumentation because of the positive momentum created with IRAM and the urgent
need that a French laboratory be more strongly involved in this field (optically oriented). Indeed, in this period,
the first engineers recruitment at LAOG was intended for supporting the expected effort in VLTI instrumentation.
While recruitment and equipment acquisition were continuously backed for years by the tutellae (mostly
CNRS), the VLTI operation was delayed for some years (due to political decisions by ESO and member states).
Then the involvement turned instead to adaptive optics equipment (the GraF spectro-imager for ESO and then
the NAOS adaptive optics system for the VLT) and to instrumental research, i.e. research and development
(R&D) activities and - a quite specific characteristic - technological research (R&T), oriented toward detectors
then integrated optics.
Until 2002, the laboratory size, and specially the technical manpower, has continuously increased to achieve
the foreseen goals. The range of activities and their importance in the laboratory politics became such that the
need for a team oriented toward ”instrumental research” became obvious. Such a team, called GRIL for Group
of Instrumental Research of LAOG has then been created in early 2004. All LAOG researchers or engineers
involved in R&D or instrumental strategic discussions are supposed to participate to GRIL activities together
with students who have a substantial involvement in R&D developments (see section 14.1).
As for the other LAOG teams which have their own specificity, the instrumental research conducted by
GRIL can be dictated by different orientations, for instance defined at another level for the benefit of a larger
community. However, when it comes to the actual building of instruments, LAOG will want to keep an interest
in their scientific exploitation.
9.2 A specific expertise
The present activities of GRIL are closely related to the more-than-10 years development of instrumental and
technological projects in LAOG. Because of its history, expertise and equipment now available are markedly
oriented toward high angular observation techniques and related technological research. Instruments like NAOS
or AMBER do follow the rule while, occasionally, we may handle other projects types (e.g. WIRCAM).
Therefore, LAOG has acquired special expertise on the following topics : adaptive optics (system design, wavefront
sensors, deformable micro-mirrors), integrated optics components for interferometry (conceptual design,
characterization, test), large instrument sub-systems design and interfacing, system and sub-system management,
integration and test, instrumental control, interferometric data treatment. LAOG now has the appropriate
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equipments for these tasks, from dedicated design software to adapted laboratories and an integration hall.
The use of radio-submm and optical interferometers by LAOG researchers has brought an excellent knowledge
of interferometric data processing. This was the rationale for creating in Grenoble a center of expertise in this
field (in 2000), aimed at providing software tools for the optimum use of large optical interferometers. Other
laboratories joined the process which became in 2003 the J.-M. Mariotti Center (we owe to Mariotti, a colleague
of many at LAOG, a large part of the actual VLTI concept), labeled as a ”Groupement de Recherche” by CNRS.
9.3 Organization
GRIL, as other teams, has working meetings to discuss progress in R&D activities and instrumental development.
Because of the relation between the GRIL activities strategy and the politics of LAOG in terms of instrumental
projects, technical staff evolution and technical equipment, GRIL has a specific role in the laboratory in relation
with the instrumental research and instrumental development mid to long range prospective. To this end, it
schedules dedicated brain-storming meetings for discussions of this kind aimed at making propositions to the
laboratory. For short term questions, that frequently arise in R&D and instrumentation matters, a board made
of three GRIL representatives and the management allows cross-information and decision-making.
9.4 Related activities
• Teaching activities: Members of GRIL, even not ”maitre de conférences” or ”professeur” may be involved
in teaching duties in Grenoble universities (Université Joseph-Fourier, Institut National de Physique de
Grenoble, ...) related to their instrumental expertise.
• PhD education: through PhDs in the team, a number of young scientists have benefited from the combination
of instrumentation skills and astrophysical expertise practiced in GRIL; as a result, the team is
quite efficient in terms of participation in all aspects of large instruments development, from conceptual
and technical design to their optimized exploitation.
• Education: The LAOG has been the main organizer of the EuroWinter School of Les Houches Observing
with the Very Large Telescopes Interferometer.
• Special duties: one should point out that part of the Astronomers’ instrumental involvement is service
tasks rather than research ; this part takes place in the framework Observing Services of the astronomers
( Instruments for TGE like VLT or CFHT, JMMC). Moreover several members of GRIL insure science
administration duties at the national level (ASHRA, PNPS,...) and the European level (OPTICON).
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Chapter 10
Scientific rationale
10.1 Background
10.1.1 Key astrophysical questions
The thematic priorities of the other LAOG teams point toward a number of instrumental needs, too large for
an even big laboratory to cope with. For historical reasons and complementarity with other institutes, in the
early 90’s the LAOG has focused its instrumental interest on the capability to study compact sources : environment
of stars, especially young ones, (FOST) or AGN (SHERPAS) mainly, but also micro-quasars (SHERPAS)
or embedded protostars (ASTROMOL). Recently, with the advent of improved observational techniques (e.g.
high contrast imaging with adaptive optics) that already let to spectacular results in the field, the LAOG has
put forward the case of extra-solar planets.
Studying the nearby environment of young stars with emphasis on extra-solar planetary systems calls first for
imaging capabilities with spectral resolution and high angular resolution. Further progress will come from improving
i) the achievable contrast ii) the imaging capabilities (e.g. measurement of interferometric phase) iii)
the angular resolution.
As a result, based on the instrumental expertise acquired in LAOG for more than 10 years, we have focused our
developments on optical instrumentation dedicated to making progress in these directions. In parallel, some
of us are or should be involved in other instrumental operations also related to studies of extra-solar planets,
planetary formation or stellar formation (astrometry, high spectral resolution, radial velocity spectroscopy...)
but that are outside our main instrumental objectives.
10.1.2 Related instrumental evolution
More specifically, two instrumental fields are currently evolving in the right direction to this end :
• In adaptive optics (AO) imaging, continuing system and sub-systems developments are being done on
major aspects : components (among which deformable micro-mirrors), fast low-cost computers, optimization
modes (such as high contrast AO, or extreme AO (XAO), multi-conjugate AO), laser guide star for
wavefront sensing in empty fields. . .
Part of this progress is essential to our scientific goals, especially deformable mirrors with large actuators
number and the XAO approach.
• Optical multi-telescope interferometry has also evolved a lot in a few years with major equipments (such
as VLTI) now offered to the general User. Further improvement is to come from spectacular progress
in R&D on guided optics, especially integrated optics, with the prospect that much of the present-day
components of an instrument be accommodated within one or a few stable and very small integrated
optics components.
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10.1.3 Current trend of large equipments
For our strategy, it is crucial to analyze the current long-term evolution towards larger and larger equipments.
30-60m large optical telescopes and large ground or space interferometers are prominent projects in the domain
of interest for us, and will probably largely impact the future development priorities at national levels and
further.
To stay within the instrumental domain defined above, it must be noted that this new generation of projects
includes the following instrumental cases :
• coronographic extreme-AO mono-pupil imaging (VLT-PF, EPICS) or nulling interferometers (PEGASE
or ALLADIN, DARWIN) to get access to very faint nearby features or companions
• arrays with large number of telescopes allowing for better u,v-plane coverage (VITRUV, KEOPS)
• kilometric arrays (ground or space) for access to extremely high angular resolution (OHANA-type modes,
KEOPS)
10.1.4 Increasing networking process
Another crucial aspect of the context is the continuing networking process at work at various levels. Within
Europe, thanks to the political will, new tools were made accessible to research within the 5th and 6th framework
programs (FP5, FP6) notably. A I3 network, OPTICON, has permitted to finance several international
collaborations connected to this discussion, for AO, fast-detectors and interferometry software development for
instance. Recently an additional but smaller network, ARENA, has been accepted for specific preparation of
the Antarctic use by astronomers.
The prospect of the 7th framework program (FP7) being even better financed lets anticipate that part of our
activities might be supported by such European funds.
At the national level, an important structuration is also at work, with for instance the ”action spécifique” HRA
(ASHRA) that provides projects evaluation (before funding) for INSU. A very successful result is to be found in
the creation of the JMMC, a national network intended to provide software tools to the general User of optical
interferometers. It must be mentioned that we are involved in a network (through ANR fund request) dedicated
to medication applications of adaptive optics techniques.
10.2 Strategy
10.2.1 Well defined priorities
We intend to follow the same direction as during the current ”quadrennial contract” that is focused on compact
sources and specially the nearby stellar environment and their planets, but with a further emphasis on research
and study of extra-solar planets, planetary systems and their formation. In this way, while fulfilling some needs
of all teams, as previously seen, we give more attention to an important objective of the FOST team with the
belief that LAOG may bring an important and visible contribution to the field.
As seen above, the result of this choice lies on three distinct families of observational capabilities:
• very high contrast imaging using coronographic AO systems or nulling interferometers, depending on the
angular resolution needed,
• imaging capabilities of complex objects at high angular resolution calling for arrays with a larger number
of telescopes than present-day interferometers,
• extremely high angular resolution only accessible through kilometric-size type arrays (on the ground or in
space).
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The first and last items are a definitive need for the study of extra-solar planets while the second is more
of interest for stellar formation (and AGN) studies in general since the complex topographic nature of nearby
environment of young stars cannot rely on model fitting only and rather requires real imaging capabilities.
In addition, if low to medium spectral resolutions are needed for most of the objectives, in stellar formation
studies, a spectro-imaging approach, combining both high angular resolution within not a too small field and a
spectroscopic analysis of each resolution pixel, would be ideal.
It must be noted that all instrumental approaches useful for extra-planetary studies are not retained : for
instance, astrometric capabilities, that are expected to be quite productive in some years from now but have
been chosen as their priority by other institutes.
The guiding orders of magnitude Let’s recall the basic numbers that guided the high-level definition of
the current instrumentation for these priorities to be followed.
• Spectral range: in the range 1-2.5 µm (J, H and K bands), emission is at 1000 K to 3000 K; going further
allows to probe cooler material and going shortward allows to probe the important region around Hα.
• Spatial resolution: in nearby (100 pc) star formation regions, 1 mas typically corresponds to 0.10 AU.
Investigating planet formation requires at least one milliarcsec resolution. At the wavelengths quoted
above, this implies interferometric baselines of about one hundred meters. In AGN, the outer size of dust
tori are expected to be around 3 pc. Since 10 mas @ 15 Mpc (closest AGN) corresponds to 0.5 pc, the
same resolution power is necessary.
• Sensitivity: YSO are fainter than K=5 and AGN than K=7-9. The required instrumentation is directly
constrained by this sensitivity threshold
• Accuracy: in AGN and YSO, the requested dynamic range is of the order of 1:100 to 1:1000. For the
exoplanets, the brightest Pegasids are almost 10 4 times fainter than their host stars (at 2 µm). Therefore
a measurement accuracy between 1% and 0.1% is compulsory and better is required for some specific
objectives.
10.2.2 Focusing on three complementary axii
The exposed priorities lead to the following possible directions of instrumental development, constrained by
the high-level requirements above mentioned, organized here in the three complementary families previously
analyzed :
• Improving Very High Contrast imaging capabilities Associated to a typically low spectral resolution,
VHC imaging points toward optimized AO-based imagers like the VLT Planet Finder (2 nd generation
VLT instrumentation) or nulling-type interferometers like, in the long term, DARWIN or TPF-I whose
precursors could be the PEGASE project proposed to CNES in the context of the free-flyers CfT or the
GENIE-on-ice ALLADIN project for Antarctica. The related developments are : Adaptive optics with
large number of actuators, system studies or sub-systems (e.g. fast detectors) for VHC contrast imaging
optimization, integrated optics at thermal wavelengths optimized for excellent characteristics (of spatial
filtering, low level of leakage for instance).
• Improving imaging capabilities of complex objects Associated to low-to-medium spectral resolution,
better imaging capabilities of interferometers point toward an increase of the number of baselines ;
while present-day optical interferometers (IOTA with IONIC, VLTI with AMBER, CHARA with MIRC)
are just beginning using closure phase with three telescopes, there is a good prospect for increasing the
u,v-plane coverage as the PdB IRAM interferometer did in the past when going from the initial 3 antennae
to the current 6 antennae, i.e. a factor x15 in the phase information level. The related developments are :
continuing integrated optics development toward more complex and performant components (recombinators
with 4, 6 or 8 beams ; improved throughput ; other functionalities like optimized fringe tracking
components) ; AO system development dedicated to large interferometers auxiliary telescopes.
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• Improving High Angular Resolution observation capabilities The goal is here to go beyond the
current limit (typically several milliarcsec at J to K with the VLTI), requiring kilometric baselines for
near-IR interferometry (providing down to 10 − 4 arcs) ; it can also be, operational constraints permitting,
to use (segments of) large single-dish telescopes (ELT-type, under completion phase) at visible wavelengths
by pupil masking techniques until AO systems can work at V on large telescopes. The related
developments are also to be found in progressing in integrated optics on one hand, in progressing on the
system optimization needed for combining AO use with pupil masking on the other hand.
10.2.3 The principles of our involvement
Our philosophy is based first on the acquired experience in Grenoble of course but also in other places :
high angular resolution techniques are complex and benefit must be taken from all the available experience
accumulated in the laboratory or on the sky. Our developments in integrated optics (such as the IONIC longterm
R&D) were tightly based on the anterior work on FLUOR at Observatoire de Paris while the design of a
large AO-based instrument (like NAOS) was based on the successful approach followed for ADONIS at ONERA
and Observatoire de Paris.
As a result, we want to reach the best coherence possible of our strategy with the national instrumental politics.
As previously reminded, this one is well structured at the national (or international) level so that our own
views are regularly confronted with the perspectives at this higher level and, for R&D notably, more and more
defined within the context of networks. Because of this and of the increasing complexity and cost of the TGE
general-User instruments, LAOG naturally acts within consortia for large projects.
The second guiding principle is to keep a good balance between instrumental research and involvement in large
instruments operations. A major, and rather specific, element in the LAOG strategy is in the strong willing to
keep this balance in the long-term since it provides very useful inputs, drawn from R&D results, to conceptual
studies of future large instruments. It is also a determinant piece of politics for the resources management. In
practice, LAOG may program one to two large projects in parallel to R&D programmes.
A third elements of politics is our intention to keep involved in spatial projects through R&D contracts where
our expertise in system conception and specific components development and characterization can be useful.
The question to get even more involved in the future is open, depending on the technological orientation of
space projects.
10.2.4 A logical sequence
To make it robust, the LAOG has always tried – and wants to do so in the future - to built its detailed strategy
on the wish to participate in the whole sequence of phases that go from instrumental research to general-use
instruments on TGE. This insures the best transfer of expertise from the technological field to the instrumental
design. The decision to get involved in given projects is therefore largely constrained by continuity needs : it
can be seen in the graph (Figure 10.1 that the projects IONIC, IONIC/CHARA, VITRUV belong to such a
sequence, as do IODA, PEGASE, DARWIN, or MMD, dedicated AO systems, or also NAOS, VLT-PF, EPICS.
With appropriate collaborations, the goal to participate in each phase of such sequences, i.e. of a given instrumental
objective, can be met provided that R&D be based on the present expertise at LAOG and that,
obviously, large instruments be selected by agencies for funding. It must be noted that this strategy implies
a commitment to already engaged operations. The VLT-PF for instance results from a 3-years long pre-study
and, providing decision is confirmed in late 2005, implies the LAOG commitment.
The resulting strategy can be summarized as follows, by emphasizing the priorities that were followed during
the current ”quadrennial period”:
• strengthening our efforts in R&D on IO for interferometry aiming both at developing 2 µm imagers
(VITRUV) and progressing towards 10 µm nulling interferometry (DARWIN)
• developing a new technology of deformable mirrors in view of the instrumental needs of ELT as well as
small telescopes
• taking benefit of the expertise acquired with NAOS to promote a concept of extreme AO-based imager
(VLT-PF)
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Figure 10.1: The logical link between past or engaged R&D and instruments organized according to the three
families: adaptive optics, interferometry, detectors and cameras. The logics described in the text is made visible:
for instance, how NAOS building prepared us to promoting the VLT-PF, the VLT-PF pre-studies prepared those
on EPICS for an ELT; the same applies with AMBER now followed by VITRUV, which in turn benefits from
the success of IONIC-type R&D. In addition, related R&D activities are grouped within boxes to make their
connection clear. It must be emphasized that the various projects shown belong to only three different families,
each with R&D and instrumentation, that are largely focused on decisive progress in eitheir very high contrast
imaging, imaging capabilities or very high angular resolution observations
• providing a 2 µm 3-beams spectro-imager (AMBER) to ESO and use the experience of it to study and
promote a faster imager (VITRUV) for the VLTI.
It is very satisfying to notice and recognize that all of these goals, presented in the previous LAOG evaluation,
have been met as can be seen in the next chapter.
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Chapter 11
Results
11.1 Towards high dynamic with Adaptive Optics (AO)
The LAOG adaptive optics activity is actively contributing to the development of the current European efforts
to provide more efficient and performant adaptive optics (AO) systems for astronomy, but also for other applications,
such as ophthalmology, laser beam shaping, etc. In order to achieve these goals, LAOG is mainly acting
in two different directions, i/ the development of new components for the future generations of AO systems and
ii/ the contribution to the manufacture of AO instruments for ESO with other French and European partners.
11.1.1 The first generation: NAOS
The NACO instrument on the VLT UT-4 telescope consists of the NAOS adaptive optics system, providing
diffraction-limited images in the near infrared, and of its companion science camera, CONICA, equipped with a
1024 × 1024 ALLADIN detector covering the 1–5 µm spectral domain (Figure 11.1). CONICA was developed
under the responsibility of the Max-Planck Institute for Astronomy in Heidelberg. The main technical features
of NAOS are a piezo-stack deformable mirror with 185 actuators and a separate tip-tilt mirror, two selectable
Shack-Hartmann wavefront sensors operating either in the optical (450-950 nm) or in the near-IR (800-2500
nm) range, both featuring up to 14 × 14 sub-apertures. NAOS has been manufactured by a French consortium
including ONERA, Observatoire de Paris and LAOG. LAOG was in charge of the design and manufacturing of
the opto-mechanical structure (P. Rabou; E. Stadler), the instrument control system (J. Charton), the visible
wavefront sensor (P. Feautrier) and the integration and tests of the whole instrument in its static mode, i.e.
without the AO components 1 (P. Kern; P. Puget). LAOG was also responsible for the NAOS Science Group (A.-
M. Lagrange Project Scientist) and therefore LAOG scientific staff was heavily involved in the commissioning
activities 2 (J.-L. Beuzit, G. Chauvin, D. Mouillet - Figure 11.2). NAOS and CONICA are now widely used by
the ESO community amongst which several LAOG astronomers (cf. FOST).
11.1.2 The high contrast imaging: VLTPF
For its second generation instrumentation on the VLT, ESO has supported two 2-year concurrent Phase A
studies for a so-called ”Planet Finder” dedicated instrument, the first one led by the Max-Planck Institute for
Astronomy in Heidelberg and the second one led by LAOG (P.I. J.-L. Beuzit). The prime objective of such an
instrument for the VLT, initially proposed by LAOG (D. Mouillet) will be the discovery and study of new giant
extra-solar planets orbiting stars, by direct imaging of the circumstellar environment. The challenge consists
in the very large contrast between the host star and the planet, larger than ∼ 12.5 magnitudes at very small
1 Charton J., Hubert Z., Stadler E., Schartz W., Beuzit J.-L., 2003, System level simulation of micro-mirrors for adaptive optics
in Specialized Optical Developments in Astronomy. Atad-Ettedgui, E.; D’Odorico, S. Ed.. SPIE Proc., 4842, 207-218.
2 Mouillet D., Lagrange A. M., Beuzit J.-L., Moutou C., Saisse M., Ferrari M., Fusco T., Boccaletti A., 2004, Extra-solar Planets:
Today and Tomorrow in High Contrast Imaging from the Ground: VLT/Planet Finder; ASP Conf. Ser. 321, 39.
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Figure 11.1: NAOS-CONICA installed on the Nasmyth B platform of the 8.2-m VLT YEPUN Unit-4 Telescope.
From left to right: the telescope adapter/rotator (dark blue), NAOS (light blue) and the CONICA cryostat
(red). The control electronics is housed in the white cabinet.
angular separations, typically inside the seeing halo. Therefore the whole design of such an instrument shall
be optimized towards reaching the highest contrast performance in a limited field of view and at the shortest
possible distances to the central star. Keeping this prime objective in mind, it is obvious that many other
research fields will also benefit from the instrument performance, in the domains of brown dwarf studies, protoplanetary
disks, mass loss of stars, etc. The Planet Finder instrument will greatly contribute to the next 10
years of studies in the research field of extra-solar planets, already very active, particularly by offering the first
direct detections of planets more massive than Jupiter at various stages of their formation, in the key separation
range of 1 to 100 AU. Migration mechanisms could then be better understood. The complementarities of direct
imaging with other detection methods, in terms of targets, detection biases and measured planetary parameters,
and more specifically, the combination with other projects like HARPS, COROT, VLTI/PRIMA, JWST and
Kepler will offer promising new avenues in this field. The present indications that massive distant planets could
be numerous will be firmly confirmed or denied by the Planet Finder, if the number of observed targets with
relevant detection limits is statistically acceptable, i.e. greater than typically 200. This would in particular
fully justify a large effort in an extended observational survey of several hundred nights.
The key features of such an instrument include an extreme AO system allowing to reach Strehl ratios of 90% in
the H band under reasonably good seeing conditions, a coronagraphic module, harboring a classical Lyot device
as well as one or two phase mask devices (4-quadrant phase mask and/or apodized Lyot for instance) allowing
to reach very small angular separations between the host star and the planet candidates, a differential imaging
camera dedicated to infrared imaging in one or two simultaneous spectral bands or two orthogonal polarization
as well as low resolution long slit spectroscopy (R ∼ 50 to 500). For stability reasons, the instrument will not be
directly attached to the telescope Nasmyth rotator but rather installed on the Nasmyth platform. All the above
described modules and sub-systems will be located on a fixed bench, controlled for vibrations and temperature
variations and equipped with an environment control.
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Figure 11.2: NAOS-CONICA image of the double star GJ 263 for which the angular distance between the two
components is only 0.030 arcsec. The raw image, as directly recorded by CONICA, is shown in the middle, with
a computer-processed (using the ONERA MISTRAL myopic deconvolution algorithm) version to the right. The
recorded Point-Spread-Function (PSF) is shown to the left. The CONICA pixel scale of 0.01325 arcsec/pixel
was used with the FeII filter (1.257 µm). The exposure time was 10 seconds. This image was obtained during
the NAOS/CONICA commissioning run in November 2003.
Following presentations of the results of our phase A study to an ESO-appointed Review Board in December
2004 and to the ESO Scientific and Technical Committee in April 2005, our proposal has been recommended for
phase B. We are currently preparing the contract for this phase B with ESO and also considering the possibility
to include members of the competing team in order to broaden the capabilities of the Planet Finder instrument.
First light of the Planet Finder is foreseen to occur by end of 2009 or beginning of 2010.
11.1.3 Instrumental Research and development activities
DEFORMABLE MICRO-MIRRORS
The LAOG R&D activities in adaptive optics are focused on the development of new deformable mirrors for the
next generation of AO systems. The goal is two-fold: i/ obtain smaller and cheaper mirrors for astronomical
applications such as AO systems for interferometry, Multi-Object Adaptive Optics (MOAO) systems, etc., or
for non astronomical applications like ophthalmology, laser beam shaping, telecommunications; ii/ manufacture
mirrors with several thousands actuators for astronomical applications in the fields of eXtreme AO, AO systems
for the Extremely Large Telescopes (ELT), etc. These innovative works lead to three patents and two technology
transfer during the 2001-2005 period (see 14.3).
Magnetic deformable mirrors This technology is particularly well adapted to the production of low order,
large stroke mirrors, therefore allowing to correct all wavefront errors without the need for the usual second tiptilt
stage. These mirrors will for instance be used for interferometry, MOAO, ophthalmology, laser beam shaping,
etc. We have already produced several 52-actuator devices (Figure 11.3), including their control electronics,
and we are now offering these devices through two commercial partners (see below and in section 14.3). Further
developments are considered in order to increase the number of actuators up to 400. The typical characteristics
of these mirrors are given below:
• the minimum actuator step is 2 mm with the current technology
• the typical best-flat surface is ∼ 5 nm RMS (mirror surface)
• typical strokes for the low order modes range from 10 to 15 µm (possibly up to 100 µm)
• the linearity remains below 2% for large strokes (below 1% for +/- 5 µm stroke)
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Figure 11.3: Left: the first 52-actuators magnetic deformable mirror prototype. Right: the MEMS-based
electrostatic deformable mirror prototype
• there is no measurable hysteresis
• the mirrors can be used in systems with a typical rejection bandwidth of 100 to 200 Hz
• standard coatings such as protected silver can be applied on the mirror membrane
Electrostatic deformable mirrors The second technology is based on MEMS (Micro Electro Mechanical
System) technology. It is first targeted at high performance applications needing a very large number of actuators,
but we keep it compatible with potentially high volume applications such as ophthalmology. This
compatibility allows us to use high-end manufacturing facility at CEA-LETI, that would otherwise be inaccessible.
The current prototype, based on a novel (patented) actuator concept is being tested at LAOG. It already
shows unique features, such as a large stroke (5 µm) with a truly continuous optical surface. This development
is now being funded by EC as a specific OPTICON JRA1 workpakage, led by LAOG. Our goal is to provide a
2000-actuator deformable mirror by the end of 2007.
Industrial development These innovative works led to three patents and two technology transfers during
the 2001-2005 period (see the details in 14.3). The production and selling tasks of MMD have been transfered to
two dedicated companies (FLORALIS for astronomical applications and Imagine Eyes for all other applications
under specific licensing contracts, allowing LAOG to keep focused only on the very R&D, be it for components
only until now or possibly extended to the full system later.
OTHER TASKS
Laboratory test bench As part of the prototyping efforts during the Planet Finder Phase A study, a simple
adaptive optics test bench has been set-up at LAOG to validate various new control concepts. For instance
the possibility to fully servo the position of the instrument pupil using only the data from the Schack-Hartman
wavefront has been demonstrated (G. Montagnier, master thesis) using this test bench. These experimental
validations were conducted in collaboration with our colleagues from ONERA (T. Fusco and M. Nicolle).
Integral Field Spectroscopy with Adaptive Optics The research is progressing on the instrumental
issues of the coupling of Integral Field Spectroscopy (IFS) with adaptive optics. This field of research was
initiated at LAOG in 1994 with one of the first IFS instruments used with AO (GraF spectrograph successfully
used with the ADONIS at the ESO 3.6m telescope 3 ) and pursued with the implementation of the GriF mode
3 Chalabaev, A.; Le Coarer, E.; Rabou, P.; Magnard, Y.; Petmezakis, P.; Le Mignant, D., 2002; The GraF instrument for
Imaging Spectroscopy with the Adaptive Optics, Experimental Astronomy, 2002, 14, 147
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on PUEO at CFHT. The IFS experts (A. Chalabaev and E. le Coarer) have recently contributed to the studies
of the spectroscopic option for the VLT-PF instrument and are now studying the best possible integral field
spectrograph designs for ELT’s.
MCAO and GLAO studies In the frame of our collaboration with ONERA, a study has been initiated on
the determination of the sky coverage for Multi Conjugate Adaptive Optics (MCAO). An optimized algorithm
has been developed to improve previous sky coverage estimates, by more accurately accounting for instrumental
and observational parameters such as the wavefront sensor concepts (star or layer oriented), the guide stars
relative positions in the field and the guide star magnitude histogram. This work was conducted by A. Blanc
on a 2-years contract financed by ESO.
Another critical point for the conception of the next generation large field adaptive optics systems is the
optimization of the wavefront sensing approaches. As part of these efforts, a ONERA-funded PhD thesis has
been started in 2003 to address this question for the particular case of Ground Layer Adaptive Optics (GLAO)
systems (co-directors: by T. Fusco and J.-L. Beuzit).
11.2 Bringing optical interferometry into mainstream astronomy
The LAOG interferometric activities aims at bringing optical interferometry into mainstream astronomy. To
fulfill this goal LAOG is carrying a multiple front effort going from instrumental research and development,
instrument design and construction to real data analysis and interpretation.
Optical interferometry has been developed in LAOG since 1995 through the participation to the Very Large
Telescope Interferometer run by ESO and national actions on GI2T and FLUOR. Then LAOG has started an
R&D activity in integrated optics in 1996 and has participated in 1998 to the VLTI/AMBER instrument.
11.2.1 The classical approach: AMBER
AMBER is the three-telescope beam combiner for the VLTI operating in the J, H, and K bands and equipped
with a spectrograph whose spectral resolution can reach 10000. It has been manufactured by a European
consortium including the Observatoire de la Côte d’Azur, the Université de Nice, the Observatory of Arcetri
(Italy), the Max-Planck Institute for Radioastronomie in Bonn (Germany) and the LAOG. This instrument
has involved a major part of the LAOG resources during 6 years, for its design, its manufacturing and its
integration. LAOG was in charge of the instrumental control device (resp. E. Le Coarer ), of the data reduction
software (resp. G. Duvert), and of the assembly, integration and tests (resp. K. Perraut). The laboratory is
also responsible of the leadership of the scientific group (F. Malbet, Project scientist) and the co-management
of the projet (resp. P. Puget then P. Kern).
Challenges The main challenges of AMBER consists mainly in the original design of such an instrument.
The main idea was to merge the French expertise in interferometry both in high precision (FLUOR experiment)
and spectro-interferometry (GI2T experiment). The AMBER concept is directly inherited from these two
experiments using part of their technology: optical fibers, dispersed fringes,... In addition, we have developed
a new way to process the signal with a very strong emphasis on internal calibration of all the instrument from
the entrance to the pixels. It has produced a new data reduction algorithm based on carrying waves that we
have called ”Pixel-to-Visibilities” processing. This processing relies on a full calibration of the internal effects
to produce a matrix of the instrumental transfer function. The complex visibility is therefore a direct product
from this matrix to the flux detected on the pixels.
Current status AMBER has already produced a full hand of scientific results on the luminous blue variable
Eta Carinae (Petrov et al. 2005, ESO conference), the evolved binary system Gamma Velorum (Petrov et al.
2005, ESO conference), the Be star HD 50013, the young stellar system MWC 297 (Malbet et al. 2005, ESO
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Figure 11.4: Left: the AMBER instrument in the VLTI focal laboratory at the ESO Paranal VLT observatory.
Right: first AMBER observations with the three Unit Telescopes on 70 Aql with the medium spectral resolution
in K band. From ESO Press Release 07/04.
conference) and some progress in the qualification of the instrument for exoplanet detection. The result on
MWC 297 is developed in the FOST part.
AMBER expected on-sky performances in terms of limited magnitude, spectral resolution and dynamic
range have no equivalent. This translates into mandatory requirements for the VLTI in terms of dynamical
cophasing and throughput that have not yet been met. Informations gathered during AMBER commissioning
periods have been a key point to reveal current VLTI weaknesses (various sources of vibration, degradation
on PSF in the delay-lines tunnel, etc. yielding low instrumental contrast). Much is expected from the VLTI
recovery plan under progress in order for AMBER to reach its final performances.
The instrument has been offered to the European astronomical community for the first time for the period
P76 (starting 1st Oct 2005) and proposed again for P77. The commissioning period is still continuing with
long periods of waiting for improvement of the performance of the VLTI subsystems. The VLTI is in 2005
following a recovery plan that should in principle help to eventually reach the AMBER ultimate performances.
Most of the remaining actions for LAOG people are now commissioning runs, data reduction, support to the
astronomical community for preparing observations and optimally using the AMBER ability, science planning
for the Guaranteed Time Observations (GTO) and publication.
Several PhD students have taken part to this project: P. Mège at the concept study, C. Gil during integration
in Grenoble, E. Tatulli and F. Millour for the data reduction algorithms. A CNRS postdoc has been hired to
focus on the astrophysical interpretation of commissioning data: W.-J. De Wit. This instrument is being used
by member of the FOST team and SHERPA team. An internet web site is being hosted by LAOG at the following
address: amber.obs.ujf-grenoble.fr. Fabien Malbet is the main responsible for this activity at LAOG.
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Figure 11.5: Image of the binary star λ Virginis obtained by aperture synthesis with the IONIC3 instrument
on IOTA. At the bottom, the beam combiner IONIC3. From Monnier et al., 2004, ApJ, 602, L57.
11.2.2 The innovative integrated optics: IONIC on the IOTA and VLTI interferometers
LAOG has developed in a close partnership with the Harvard-Smithsonian Center for Astrophysics the focal
instrument (called IONIC3) combining three telescopes of the IOTA Interferometer (Traub et al., 2004, SPIE,
5491, 482). This instrument, whose first light has occurred in 2002, uses the integrated optics techniques developed
by LAOG with its local partners (IMEP and LETI) and significantly financed by the CNES. IONIC3 is the
more sensitive and the more accurate imaging instrument operating in the near infrared range. It is now used
by about ten American and European teams and provides scientific results in the field of imaging of multiple
systems (Figure 11.5), pre-main sequence stars, evolved stars (Kraus et al., 2005, AJ, 130, 246). J.-P. Berger
is the main responsible for this activity at LAOG.
LAOG has also delivered two integrated optics beam combiners to ESO to equip the focus of the VINCI
instrument. The first one, made by ion-exchange technique and operating in H band, has been tested at
Paranal during the summer 2002 (Le Bouquin et al., 2004, A&A, 424, 719). The second one, made by silica-onsilicon
etching technique and operating in K band, has been installed in Paranal during the summer 2004. The
latter is routinely used with VINCI for VLTI test such as for the first combination of the Auxiliary Telescopes
(Figure 11.6).
11.2.3 Combining up to eight telescopes of the VLTI array: VITRUV
In the framework of the European Interferometry Initiative (EII) within the FP6 OPTICON program (see
”European involvement” chapter in this report), we have conducted the concept study for a second generation
instrumentation for the VLTI. It consists of a spectro-imager based on the integrated optics techniques aimed
at combining 4 to 8 beams from the VLTI to produce aperture synthesis images in one single night. The work
consisted in several R&D developments financed by the CNES and the BQR of UJF University (4-way beam
combiners, 4T/8T workbenches, end-to-end lab and numerical modeling, system studies, image reconstruction,
...) but also the preparation of the science cases in collaboration with P. Garcia in Porto (chair of the Science
group).
This concept and all related studies have been presented at the ESO Workshop The Power of Optical/IR
Interferometry: Recent Scientific Results and 2nd Generation VLTI Instrumentation, held in Garching in April
2005. This project has been recommended by the Science Council of the EII to ESO, but is still waiting for the
beginning of a phase A study. F. Malbet is responsible for this activity.
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Figure 11.6: Left: Integrated optics two-telescope beam combiner for the VINCI instrument of the VLTI.
Right: first fringes obtained with the Auxiliary Telescopes of the VLTI on HD 62082 by means of the integrated
optics beam combiner in the K band (ESO Press Release 06/05).
11.2.4 Instrumental Research and development activities
Lab workbenches IONIC passed and future on-sky experiments rely on a intensive laboratory effort whose
aim is to characterize as much as possible all the performances in lab before any shipment. This has required
the development of new testbeds such as an industrial level connectorization bench to plug fiber V-grooves to
integrated optics chips, or a full VLTI 8-telescope simulator (Jocou et al., 2004, SPIE, 5491, 1351).
An infrared camera dedicated to these interferometric workbenches has been fully developed in LAOG in
collaboration with the LESIA (Observatoire de Paris) for the clock sequencer. This camera uses a PICNIC
infrared array produced by the Rockwell Science Center in the US. The main features of this detector are:
256x256 pixels of 24 µm size, sensitive to the [0.9 µm; 2.5 µm] range, CMOS technology allowing multiple
non-destructive readout and image windowing, readout noise of about 40 e − . Such a lab camera is required for
the Vitruv demonstrator as well as for measuring interferometric signals coming from a 8-telescope combiner.
The PICNIC camera is currently under its final tests: the cryogenics and the readout electronics sub-systems
were successfully accepted, the first images of the whole system at cold temperature using the ”MUX” was
recently obtained (electrical model of the detector used to debug the system before using the science grade
detector). This camera will be delivered to the laboratory before the end of 2005.
Integrated optics for DARWIN: MAII, IODA LAOG is involved in R&D programs dedicated to the
preparation of the ESA DARWIN mission (Léger et al., 1996, A&SS, 241(1), 135). This mission is aimed at
discovering life on Earth-like exoplanets and therefore is extremely challenging on the technical side. One of
the most critical concerns is the ability in this nulling experiment to perform the most efficient modal filtering
to achieve very high dynamic range and main star extinction mandatory for detection of Earth-like planets. In
this context, single-mode waveguides have been identified as one of the most promising solutions (Ménesson et
al., 2002, JOSA, 19(3), 596). On this basis of its expertise in integrated optics for interferometry, LAOG has
contributed to three ESA R&D contracts dedicated to the DARWIN mission by:
• providing the integrated optics beam combiner of a nulling bench in the H band in the framework of
the Multi Aperture Imaging Interferometer, (MAII, an ESA contract). The project under direction of
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Figure 11.7: PICNIC low noise infrared camera during the integration tests, before delivery
Alcatel Space Industry (ASI) was based on a large consortium 4 . Two kinds of 2-telescope beam combiners
have been provided using the IMEP/GeeO and LETI standard telecom technologies dedicated to 1.5 µm
wavelength. At the end of the contract at the beginning of 2004, we have obtained nulling at a 10 −6 level
with a laser source and at a 10 −4 level with a broad band source (with a width of 100 nm), to be compared
with the 10 −3 level obtained with a 20 µm-hole and a CO2 laser at 10.6 µm (Ollivier, 1999, PhD thesis).
• proposing the theoretical analysis of the integrated optics capabilities in the Achromatic Phase Shifter
(APS) manufacturing (a contract led by IAS, Orsay).
• developing specific waveguides for the full DARWIN spectral domain (i.e. [4 µm; 20 µm]). IMEP has the
leadership of this program with strong contributions of LETI for technology developments and LAOG
for sample tests. ASI contributes for management tasks, and LPMC in Montpellier provides promising
chalcogenide technologies. This 2-year development that will end in December 2005 has allowed to achieve
the first single-mode hollow-metallic waveguides in the mid-infrared range (Figure 11.8 - Labadie et al.,
2005, A&A, in press).
Post doctoral and doctoral students (P. Haguenauer, E. Laurent, L. Labadie) conducted these activities with
the support of the technical team. For all of the contracts Pierre Kern was responsible for LAOG.
Micro-piezoelectric fiber positioners To answer several issues about fine injection into fibers (IONIC,
VITRUV), we have developed a new generation of micro-positioning devices including mini-sensors for submicrometric
position measurements (Preis et al., 2004, SPIE, 5491, 1379). This device contains a piezoelectric
tube on which there are five metallic electrodes. The micro-positioning device will eventually be integrated in
the VITRUV project in order to control very precisely the position of every fiber at the focus of each telescope.
The responsible is O. Preis.
4 (IMEP, CSO Mesure, GeeO, LETI, LAOG, ASI)
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Figure 11.8: Left panel: Process flow of Hollow Metallic Waveguides (HMW) manufacturing. I: Silicon 4
inches wafer - II: Guide definition by photo-lithography and RIE - III: Thermal oxidation and gold deposition -
IV: Gold and silica wet etching - A: P yrex T M 4 inches wafer - B: Photo-lithography and P yrex T M wet etching
- C: Gold deposition - D: Photo-resist stripping - F: Anodic bonding. Middle panel: photograph of a HMW
input using Scanning Electron Microscope. The Pyrex cover is maintained by anodic bonding on the silicon
substrate. The etching depth is equal to 10 µm. The gold deposition is thicker on the bottom part of the
wave-guide with respect to the lateral walls. Right panel: diffraction-limited spot corresponding to the output
flux of the waveguide at 10.6 µm. X axis in pixels. From Labadie et al., 2005, A&A, in press.
Spectro-Polarimetric Interferometry To address the promising issue of obtaining spectro-polarimetry at
the milliarcsecond angular resolution, we have been involved both in the theoretical modelling of the interferometric
observables in polarized light, and in commissioning the polarimetric mode of the French GI2T/REGAIN
interferometer (Rousselet-Perraut et al., 2005, A&A, submitted). Modelling the effect of instrumental polarization
on interferometric performances allows us to propose some recommendations for the VITRUV concept
(Sect. 11.2.3). K. Perraut (responsible) and J.B. Le Bouquin (PhD) are concerned.
Data processing Mainly within the AMBER project, but also within the VITRUV and DARWIN/PEGASE
studies, we have developed an expertise in interferometric data processing and in particular in single mode
interferometry (Tatulli et al., 2004, A&A, 418, 1179). We have developed a new algorithm to reduce AMBER
data (Millour et al., 2004, SPIE, 5491, 1222), but also other types of multi-axial data, using linear algebra
and generalizing the so-called ABCD algorithm. We have investigated the sources of biases due to atmospheric
jitter and the limits of the instruments in terms of field of view. This work has been mainly the work of PhD
students P. Mège, E. Tatulli, J.-B. Le Bouquin and F. Millour under the supervision of A. Chelli, F. Malbet
and G. Duvert.
11.2.5 JMMC and European Interferometry Initiative
The Jean-Marie Mariotti Center (JMMC) is an Expertise Center in Optical Interferometry, aiming at coordinating
the French efforts in high angular resolution. Initiated by LAOG and OCA in collaboration with a dozen
of other French laboratories, the JMMC has installed its coordination center at LAOG, where a project team
produces the “software instruments” needed in data reduction and analysis tools and in preparation software for
the new interferometric developments, especially for the VLTI. The contribution of LAOG has mainly consisted
in providing the software ASPRO to prepare interferometric observations. This software is originating from the
GILDAS suite where software has been developed for the radio interferometry at IRAM. The responsible for this
software is G. Duvert. A java-based interface has also been developed for an easy use by external astronomers.
This software has been complemented by the search of calibrators (searchCalib). ASPRO became the first
virtual observatory tool, since it searches the CDS catalogs to retrieve the information required to select good
interferometric calibrators. The software is adapted every semester to the new VLTI configuration provided by
ESO. Another task of LAOG staff is to provide support to JMMC users and is recognized as a CNAP duty.
There is a strong connection between the persons working on the projects or on the R&D and the ones
involved in JMMC. Some of them are indeed taking part to both activities.
This activity has naturally been extended at the European level where several members of our laboratory
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have taken responsibilities: A. Chelli (EII board, Coordinator of JRA4), G. Duvert (PI of a JRA4 workpackage),
P. Kern (OPTICON board), C. Perrier (EII science council), G. Zins (project manager of a JRA4
work-package). The JMMC and EII activities are developed in a separated chapter in this report.
11.3 Cameras and detectors
11.3.1 Towards wide-field cameras: WIRCam
WIRCam (Wide-field InfraRed Camera) is the second instrument of the Wide Field Imaging Plan of the Canada
France Hawaii Telescope (CFHT), providing a 20.5 × 20.5 arcminute field of view in the infrared ([0.9 µm; 2.4
µm]), and completes in the infrared the MegaCam instrument operational on the CFHT since January 2003.
The LAOG, under the lead of the local project manager E. Stadler, was responsible of the cryovessel design and
manufacturing, including the filter wheels design and control/command. The LAOG was also responsible of the
cryogenic system design, manufacturing and testing and of the temperature regulation (optics and detectors)
as well. The optics was developed by the University of Montreal and the detectors control was performed by
the CFHT.
A challenging thermal design. This innovative instrument is based on four Hawaii 2RG detectors arrays
developed by Rockwell in a close buttable package. This camera is designed to be placed on the prime focus
of the 3.6 m CFHT telescope to take benefit of the simpler opto/mechanical design for a wide-field camera.
It uses a Gifford Mac-Mahon closed-cycle cryo-cooler to avoid strenuous daily re-fillings on the telescope due
to poor accessibility. An optimal thermo-mechanical design has been defined to meet the stringent stability
requirements with minimal thermal losses. To provide excess cooling power was not possible due to weight
constraint on the camera of 250 kg. As the cryo-cooler must be easily dismounted for maintenance operation,
the cooling power is transmitted by a system of two cones fitted together, one male and one female, made of
OFHC copper and having exactly the same shape. The thermal link between the two cones is enhanced by using
ultra-high vacuum grease. A tunable load between the two cones is applied by a system of titanium springs.
All the cold structure is attached to the warm part of the cryostat by ten G12 composite twin blades.
Thermal-mechanical modelling. In the past decade, new computing tools have been offered to the system
designers in terms of thermal and mechanical modeling. In addition to an overwhelming increase of computer
capabilities, these tools are now mature enough to drive the design of complex astronomical instruments, in
particular if these instruments have to be cooled. This allows to better understand the cryogenic performances,
which is a huge advantage in a new design approach, and to waste time during the instrument integration.
A complete thermal-mechanical model of the camera using Finite-Element Analysis (FEA) under the I-deas
software was carried out. The capabilities of the I-deas thermal module (TMG) was demonstrated for our
particular application 5 : studies included conduction, radiation and free-convection management, variations of
the cooling power and thermal characteristics of the materials as a function of the temperature, and studies in
permanent regime and transient analysis (Figure 11.10).
The WIRCam cryovessel was successfully installed on the CFHT telescope by December 2004 with a team
of LAOG people and has obtained its first light in March 2005 after the optics and detector integration (Figure
11.9). A temperature regulation of the detector at the 0.002 K level was obtained on the telescope at the
nominal detector temperature of 81 K.
11.3.2 Research and development activities in photon counting superconducting
detectors
Superconducting Tunnel Junctions (STJ) Superconducting Tunnel Junctions have been developed as
photon counting detectors for a wide range of applications since they are energy resolving photon counters and
5 P. Feautrier; E. Stadler; P. Puget; 2004 ; Interest of thermal and mechanical modeling for cooled astronomical instruments:
the example of WIRCam, SPIE Proc., 5497, 149-160
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Figure 11.9: Left View of the WIRCam cryovessel during its installation on the CFHT (March 2005). Right:
raw data (no flat-fielding) from an engineering test J band image of the M17 nebula obtained in 30 s with a seeing
of 0.4 arcsec. The quadrants show the 4 detector array and the gap in between. The excellent cosmetic quality
can be judged from the zoom below. Bottom: zoom of the previous image, raw data without flat-fielding,
showing the amazing cosmetic quality of the last Rockwell infrared detectors.
can be used from the infrared (2 µm) to X-ray wavelengths with good quantum efficiency (60%) 6 . The aim
of our work was to investigate the interest of this kind of detectors for ground based low-light astronomical
applications and compare them to Superconducting Single Photon Detectors (SSPD) (see next paragraph).
Since the conventional detector arrays based on semi-conductor devices have recently progressed toward photon
counting detectors in the visible 7 , some niches have to be found for this type of detectors where conventional
devices cannot compete. The astronomical applications that could be investigated are wave-front sensing detectors
for adaptive optic systems, fringe sensors and focal plane instruments for interferometry in the near
infrared. This work has been carried out in a collaboration between three laboratories from Grenoble: the
LAOG (responsible of the activity under the lead of P. Feautrier), the CRTBT(under the lead of A. Benoit),
and the CEA-Grenoble/DRFMC/LCP (under the lead of Jean-Claude Villégier) in charge of the device fabrication
(Figure 11.11).
At the end of the last LAOG PhD thesis based on this subject, we decided to put our efforts on some slightly
different superconducting detectors, the SSPD (see next paragraph), which present important advantages compared
to STJ:
6 G. Brammertz, A. Peacock, P. Verhoeve, D.D.E. Martin, and R. Venn, Optical photon detection in Al superconducting tunnel
junctions, Nucl. Inst. and Meth. A, 520, 508 (2004)
7 C. D. Mackay, R. N. Tubbs, R. Bell, D. J. Burt, P. Jerram, and I. Moody, Sub-electron read-out noise at MHz pixel rates, Proc.
SPIE, 4306, 289 (2001)
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Figure 11.10: thermal modeling of WIRCam using FEA analysis and the Ideas/TMG thermal modelling
software. Left: thermal model in the steady state of the filter wheels cage and the optical barrel; right:
thermal model of the cold finger which transmits the cryogenic power to the cold structure.
• Devices simpler to manufacture, low cost (one single active layer)
• Far higher speed (1 GHz instead of 10 kHz)
• Developments supported by numerous practical applications, including commercial ones, contrary to STJ.
Superconducting Single Photon Detectors (SSPD) Niobium Nitride (NbN) Superconducting Single-
Photon Devices are sensitive to radiation from UV to mid-IR. In terms of speed and sensitivity, they outperform
any semiconductor and superconducting photon counters. They reach Quantum Efficiency (QE) of 20-30% at
wavelengths of [1.3 µm; 1.55 µm], related to intrinsic QE close to 100%. Dark counting rate is extremely
low: 10 −4 counts per second and less. Measured Noise Equivalent Power (NEP) is about 5.10 −21 W/ √ Hz in
a wavelength range of [0.5 µm; 1.5 µm]. NbN SSPD is practical devices for non-invasive optical analysis of
CMOS circuits and can be successfully used for quantum communications and quantum cryptography. These
new detectors are developed in a collaboration with the CEA Grenoble and the Laboratoire de Spectrométrie
Physique de Grenoble. Some first devices have been recently produced (Figure 11.11) and are currently under
performance evaluation. These detectors are particularly interesting for the Lippmann spectral detectors (see
Prospective).
Figure 11.11: Left: 3x3 pixel array of 30 µm x 30 µm Ta-based STJ’s. Upper middle: details of the
array structure with a Scanning Electron Microscope (SEM). Lower middle: single Ta-STJ. Right Scanning
Electron Microscope (SEM) photography of a SSPD meander fabricated at the CEA-Grenoble. The width of
the stripes and the distance between them are 150 nm. Courtesy of CEA-Grenoble/DRFMC/LCP (Jean-Claude
Villégier).
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Chapter 12
Perspectives
The instrumental research and development objectives of GRIL are described here using the same frame as for the
results, distinguishing between three instrumental families. The R&D activities and instrumental realizations,
although tightly linked as previously explained, are separately described only for sake of clarity.
12.1 Adaptive optics
We describe below the projects that are proposed for the next ”quadrennial period”. The instruments come
first since there are the ultimate goal of GRIL activities. R&D is exposed afterward. Part of the projects
have already started and other are extension of previous works into a more advanced and/or more ambitious
phase. From the priority already exposed, the future activities will be preferentially directed towards extreme
AO systems development.
12.1.1 Instruments
PRIORITIES
The imminent VLT PF 2 nd generation instrument whose contract should be signed early 2006, implies
an important commitment on behalf of the LAOG with an expected schedule of the commissioning in 2010-2011,
i.e. after the end of the present prospective period. See the chapter 11.1.2 for the scope of this instrument.
LAOG provides some of the key-persons of the project and a large part of the resources for the integration and
test phase. This project is therefore a major undertaking for our laboratory with two crucial expected returns :
on the scientific side, a leading role in the survey, and on the technical aspects, an additional expertise that will
be essential for the extreme AO-based instrumentation of the ELT era.
Studies for ELT The preparation of ELTs already require conceptual studies both on the dedicated AO
systems and the instruments based on special optimization of these systems. Among the projected concepts,
an extreme AO-based imager, EPICS, takes benefit of the advances that led to the conceptual definition of the
VLT-PF, to reach the ultimate contrast for e.g. low-mass extra-solar planet search. A very preliminary study
of this concept has started with a participation of LAOG and shows the potential interest of a 3D spectroscopic
approach as we previously demonstrated with the GRaF and GRiF instruments. We wish to keep involved in
the next phases and specially the optimization of this ambitious instrument.
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Figure 12.1: All the GRIL projects for the next 5 years. Those yet to be decided are indicated as ”under
discussion”. Note that GRIL will not get involved in all of them (see text). See also caption of Figure 10.1
OPTIONAL PROJECTS
Following the opportunities that will appear in the next years, the LAOG could participate in the projects
presented below depending on the conditions and possibilities.
Interferometric telescopes AO equipment Equipping with AO systems the small telescopes used, for
instance, in large interferometers is in discussion. Observations with the VLTI AT would benefit from it and a
similar need is invoqued for CHARA. These needs may be covered by low-cost AO systems that are still to be
designed. In the event where the LAOG would start a full AO system development, we would establish a link
with these partners in order to try collaborating on this matter.
AO equipment for ELT Another direction in the longer range is a participation to the AO equipment
of ELT by providing micro-mirrors components and possibly other sub-systems of these probably large and
complex systems. AO might be employed here not only for turbulence-degraded PSF correction but also for
instrumental phase errors correction. Our involvement will largely depend on the success of R&D planned in
the JRA1 and on the conceptual view emerging from the starting studies.
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12.1.2 R&D activities
PRIORITIES
Forthcoming deformable mirrors developments in the frame of the FP6 Opticon JRA1. The main goal
is to make technological developments aiming at better performances of micro-mirrors in term of number of
actuators, stroke accuracy and other relevant characteristics for astronomical instrumentation of large telescopes
(including ELTs). A secondary objective is to develop a low-cost product to decrease the total cost of systems
for intermediate size telescopes or special applications (multi-objects FALCON approach or ophthalmological
applications for instance).
This objective should be mainly managed in the frame of the JRA1 network, with possible support coming from
other sources and/or contracts (ANR, RNTS, etc.). But, in view of the potentially complex tasks to achieve,
it is expected that a continuation within the PF7 will be necessary. In this event, LAOG is to be a natural
partner to this future networking phase.
Toward system development With the advent of small and comparatively low-cost deformable mirrors,
producing full AO systems for other applications than the large telescopes only becomes possible. A very useful
application directly related to our interferometric needs is to be found in systems dedicated to auxiliary
telescopes (of large interferometers such as VLTI or CHARA). This requires the development of whole systems
more adapted to this new configuration. We intend to proceed to such system studies and find partners to
help us provide more ready-to-use AO systems, by contributing for instance to the wavefront sensing devices,
the real-time calculators and the related control software. In this context, LAOG could be involved in the
development of a large part of such systems.
12.1.3 Means and methods
Networking Because of the large place that AO is likely going to take in the future TGE, it seems to us
quite essential to increase the expertise in the components, control and system aspects of AO systems in France,
presently mostly present at ONERA. LAOG can participate to this effort by bringing what is most specific to
Grenoble notably in system design capabilities, component development know-how, fruitful connection to local
micro-electronics institutes. This requires to increase our capabilities, mostly absorbed by VLT-PF, to a higher
level than now in order to be able to participate in the nation-wide effort beside the current operations in Paris
and Marseille. This would imply a substantial evolution in dedicated manpower, funding and room access (this
is discussed in part I).
For the same reasons, it is naturally intended to be present in the definition of programmes and tasks for the
FP7, starting in 2009. If we can increase our AO capabilities in Grenoble, our implication could be larger with
more responsibilities taken by the laboratory than presently.
Industrial development Following the development agreements related to the production and selling tasks
of MMD under contract with FLORALIS (a subsidiary of UJF) and Imagine Eyes (see 11.1.3, we intend to
keep this scheme in the near future with a prospect of several MMD produced per year as a start and likely
other productions derived from our other R&D activities.
Manpower The VLT-PF realization will be a limiting factor of our other activities during the next ”quadrennial
contract”. In order to cope with our other projects, especially the R&D ones, the LAOG must get
reinforced in some vital functions in the short term. The needs are three-fold :
- system engineering capabilities with proven project management experience, calling for a high-level specialist
of AO systems ;
- instrumental software development support; - thesis direction capabilities oriented toward AO system concept
and control, calling for a habilitated researcher or research engineer.
Moreover subtantially increasing our global capabilities in AO will require more positions at a senior level and
at least one post-doctoral position during the period.
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12.2 Optical interferometry
As for adaptive optics, part of the projects, as proposed below, have already started in the current ”quadrennial
contract” or are extension of previous works into a more advanced phase. From our priorities described before,
they will be preferentially directed towards imaging interferometry and nulling interferometry, taking benefit
from the integrated optics advances in which LAOG has taken a large part.
12.2.1 Instruments
PRIORITIES
Imaging interferometry In some years, optical interferometry routine imaging will be one of the major
achievements in astronomical instrumentation. The LAOG is strongly promoting this view and therefore is
making steps towards this accomplishment.
• VITRUV for the VLTI The LAOG has developed a proposition for a second generation VLTI instrument,
VITRUV, that is aimed at imaging with 4 at start, 8 at maximum, telescopes offering a huge improvement
in the u,v-plane coverage over AMBER. Its concepts takes benefit from the experience acquired with the
tests of IONIC on IOTA and VLTI and is precisely oriented toward the main priority of ESO known as
the ”4x4 VLTI box” that calls for 4 or more recombined telescopes, with phase reference allowing true
imaging on faint sources. The project has passed a pre-phase A study and has been proposed to ESO
in April 2005 (see section 11.2.3). Since then, the LAOG is implicitly committed to VITRUV in terms
of key-responsabilities, design, integration, tests and commissioning and is awaiting the ESO decision to
start the phase-A study. As AMBER was, this project would be an international collaboration. Several
European partners have expressed their interest in participating to the project at various levels. It must
be noted that, due to its concept, VITRUV should require slightly less resources than AMBER.
• CHARA : participation to the instrumentation In the path to VITRUV, we have developed strong ties
with Pr. Monnier at U. of Michigan in order to test key VITRUV building blocks on a real on-sky
imaging experiment. The MIRC imaging instrument of CHARA is fully compatible with LAOG integrated
optics beam combiners and offers a unique opportunity to demonstrate VITRUV imaging capability. The
eventuality to leave useful components for inclusion in a CHARA general-User instrument such as MIRC
is an open question.
OPTIONAL PROJECTS
The following projects are either space projects or dedicated to Antarctica. Because of our available resources,
the LAOG contribution can only be kept limited if VITRUV is launched as we do hope. But if it was not, our
contribution could probably be increased since our interest in these projects is important.
• PEGASE and/or DARWIN space missions LAOG is directly involved in the PEGASE project which was
presented at the French CNES space agency as an answer to the Call-for-proposal for a free-flyers mission
and is now a candidate for a Phase A study. At this stage, LAOG contributes to the scientific drivers
definition (study of gaps in protoplanetary disks and spectroscopic characterization of hot Jupiters).
Later on, LAOG could have a technical participation in the global conceptual design and the recombining
aspects if IO is retained as a solution. The involvement in PEGASE is not only motivated by standalone
objectives but also by the will to participate to the very challenging mission DARWIN that we have been
preparing by several R&D related to DARWIN (see Sect. 11.2.4), under ESA contracts. In the event where
PEGASE were not selected for a phase-A study, our involvement in the R&D preparation to DARWIN
would however be maintained because of the needs for a long-term approach to this most challenging
mission.
• Antarctica Genie-type projects Mark Swain (from JPL) spent one year in LAOG to work on exploitation
of AMBER and Antarctic interferometry. On this last subject, the LAOG has helped him to present the
problematics of Antarctic interferometry throughout Europe. Also thanks to the fruitful links between the
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laboratories of OSUG, a collaboration has grown up between LAOG and LGGE (H. Gallee) on the climate
modelling in Antarctica to model astronomical seeing, demonstrating the importance of the boundary layer
in Antarctica, of the order of 20-30 m high. The result is that seeing above this layer is exceptionally good
almost like space conditions, but at the ground level it is rather similar to other sites. Work has started
to use these results to predict performances of future instruments in Antarctica thanks to the experience
developed at LAOG for the AMBER instrument. Preparatory activities in view of astronomical use of the
Dome C Site in Antarctica have been largely reinforced early 2005 with various medium-size equipment
funding requests (to INSU/CSA and/or to IPEV) by several French laboratories and a European FP6
funding request led by N. Epchtein (LUAN), aiming at promoting first level studies of astronomical use
of the Dome C, whose funding would cover the period 2006-2007 and whose rationale must also be found
in the preparation of a large scale FP7 proposal.
In this context, LAOG is involved in the FP6 request at a limited level (6 men-months with 4 involved
persons) with the aim to participate in the definition of the astronomical goals and the studies of the
instrumental optimization for the Antarctica environment. We intend in particular to bring our expertise
in integrated optics interferometric recombiners and in interferometry at a system level.
In parallel, the LAOG may wish to look into the potentially major interest that GENIE, or an other
nulling instrument like ALLADIN, be installed at Dome C rather than on the VLTI and the compared
figures of merit to install 8m-type telescopes at Dome C as an alternative to ELTs on standard sites. We
intend to participate in the conceptual studies on which future decisions will have to be based.
12.2.2 Software development for interferometry
JMMC and European networks The detailed objectives of JMMC for this period will be described in
the report and request for renewal that will be prepared by the JMMC as a CNRS GdR (their preliminary
presentation is given in Appendix 2). We describe here how we feel, at LAOG, the orientation of the JMMC
should be for the next years.
The JMMC is currently heavily loaded by the tasks assigned by its council to which its participation, as a
major actor, to the Opticon JRA4 has added further pressure in 2004. Its present main guideline is to develop
software for the end Users of interferometry. The scheduled tasks include the development of software specific
to the optimized use of AMBER and it can be anticipated that the JMMC will try to cover the new needs
induced by the forthcoming installation of VITRUV-type (i.e. imagers) instruments on the VLTI. Moreover,
optical interferometry already joined other observational techniques in the more general framework of virtual
astronomical observatories, bringing some more constraints to the work load of JMMC.
In the future, the development of JMMC should be pursued with in mind an easy access to interferometric data
by the general astronomers both for preparing observations and for reducing them or access to science archives.
In this respect, a major outcome of JMMC is the possibility to produce and offer an image reconstruction
software optimized for aperture synthesis by optical interferometry. With all these undertakings, the JMMC is
very likely to be continued by CNRS for at least the length of the new ”quadrennial contract”.
In the longer term, it must be added that it could be beneficial to the community that the JMMC extend its
activities (services and support) to the larger domain of all high angular resolution techniques i.e. including the
specific AO data expected with ELTs.
12.2.3 R&D activities
PRIORITIES
Advanced IO components development In the domain of near-IR IO, the basic recombining functionalities
are now rather well mastered at least for 3 telescopes recombination. Future progress will come from
more functionally complex components, i.e. allowing recombination of more than 3 beams, or providing not yet
integrated functions like fringe tracking, achromatic phase shift or active functions (e.g. OPD scanning). Such
components would further strengthen the advantages of IO-based interferometric benches, therefore decrease
the overall system costs, a particularly interesting prospect for space applications.
As we did before with IOTA, we intend to test the components previously characterized in the laboratory on
the CHARA interferometer (Georgia State University) whose size and access are more adapted to this goal than
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the VLTI. CHARA is equipped with an imaging instrument, MIRC, fully compatible with LAOG integrated
optics beam combiners, which produced its first results in september 2005.
Extension to thermal IR Extension of current or programmed instruments such as VITRUV (see Section
12.2.1) to the medium-infrared (2 to 5 µm) is scientifically attractive. As such, this goal motivates R&D
activities aimed at developing IO components adapted to this wavelength range.
The ESA-funded contractual work IODA for development and characterization of IO components optimized
for the thermal IR (the range of interest for DARWIN), in collaboration with LETI/CEA and ALCATEL has
provided several potentially useful technological solutions. One of the key feature is to maintain the leakage
level to the very low level imposed by the DARWIN requirements. We now intend to continue this development
with the same partners in view of promoting an IO concept for the DARWIN nulling. LAOG would essentially
keep the same role (high level requirements definition and components characterization) with a possible
strengthening of the test phase on a nulling bench in the lab (which could be that of IAS).
MORE AMBITIOUS PROJECTS
Towards visible wavelengths ? A more open question is that of an evolution toward the widely desired
visible domain. Current limitations of the optical interferometers (absence of AO correction in V for instance)
has precluded ambitious moves into this direction and interferometry in the visible has remained limited to a few
experiences (REGAIN in France) operating generally in multi-modes. Because of the expected progress in AO
systems mentioned before and the technological possibilities, it seems reasonable to defend that using IO toward
the visible on a AO-corrected interferometer can now be projected in the new future. We may participate to
this evolution when a system study confirms that conditions are met.
ELT pupil masking and reconfiguration ? Through pupil masking and reconfiguration, diffraction-limited
resolution in V on a ELT may become possible before any AO system can be made operational, if ever. This
approach relies on the use of guided optics for the sub-pupils reconfiguration. A possible participation to such
a project undertaken at LESIA, could benefit from our simultaneous expertise in adaptive optics systems and
interferometric concepts at a system level. Our involvement will strongly depend on, obviously, the actual
collaboration possibilities and on the realism of access to an ELT for this particular science goal, at least during
the building phase of the primary mirror.
12.2.4 Means and methods
Manpower The IODA project lacks some resources that should be compensated by recruiting at a postdoctoral
level and also at a permanent position (a possibility being the University position opened in 2006). In
the mid-term, a technical position with a technological profile is necessary. The general needs for exploiting
imaging capabilities of VITRUV should be covered by a research position.
Locally, an increase of resources of the JMMC center of coordination will be necessary to fulfill its role within
the JMMC network of participating laboratories. The actual need, that depends not only on LAOG involvement
but of the whole network, is exposed in the JMMC report.
12.3 Cameras and detectors
Towards the ultimate photon detection, GRIL maintains a high level knowledge of photon detection (milimetric
wave bolometers, NIR and Visible) coupled or not to spectroscopy. The LAOG will continue to maintain an
expertise in this domain contributing to the R&D and the definition of detectors used by astronomy.
It is understandable that the astronomy community cannot afford to make alone the R&D effort necessary to
progress in this matter. For this reason, GRIL takes benefit of the growing expertise in micro and nanotechnologies
in the site of Grenoble at large (e.g. with CEA, CNRS and INPG laboratories) to build dedicated
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collaborations. Moreover, part of our work in this field is done within large networks such as ANR-funded or
OPTICON JRA collaborations.
12.3.1 Instrument support technology
Fast detectors for wavefront sensing: the JRA2 of Opticon Visible detectors fully matching the
requirements of Adaptive Optics wavefront sensors for 10-m class telescopes do not yet exist: current detectors
have frame rates which are too slow and which are too noisy for the second generation of AO systems. The
visible detectors developed by the JRA2 will be dedicated to AO applications. The scalability of these detectors
for ELT AO systems will be taken into account. The participants will attempt to define, manufacture and fully
characterize the best possible detector working at visible wavelengths which is suitable for wavefront sensors in
Adaptive Optics (AO) systems. This Joint Research Activity is closely linked to the Opticon JRA1-Adaptive
Optics. This will ensure that this detector development follows the AO requirements in terms of wavefront
sensing detectors. The detector format will be 240x240 pixels, the frame rate will be very fast (up to 2 kHz)
while the readout noise will be kept extremely low (typically below 1 e − ) by using the Electron Multiplying
technique developed by e2v Technologies, known as L3Vision. The following list of tasks concerns the LAOG
participation to theJRA2:
• Responsibility of the JRA: management of the activity, general meetings, report to the European Community,
reports and Opticon meetings.
• Responsibility of the cryogenic system: mechanical design of the cold head, cryogenic design, thermal
modeling of the whole camera, integration and cryogenic tests.
The OPTICON JRA2 being scheduled for 4 years, should continue during the next ”quadrennial contract”,
implying some continuing responsibility especially at the direction of the JRA2. As for AO components development,
this programme is likely to be proposed for a continuation during FP7. LAOG will have, in the two
next years, to express its will to keep involved in the organization of such a network and in its actual role herein.
The present day role came from the experience acquired with the NAOS visible wavefront sensor and anterior
expertise in different types of detectors (thermal IR, near IR and supraconducting devices). LAOG wishes to
keep this expertise and/or develop it further.
12.3.2 R&D activities
The future: a Lippmann spectral detector ? Following to the Lippmann color photography invention at
the end of the 19th century, we propose to renew the idea of stationary waves detection in the third dimension.
Until now, using electronic detectors rather than photographic emulsions was not possible because of their
too large size compared to the dimension required by standing waves sampling, typically one fourth of the
wavelength (i.e. about 100 nm for visible light). Recently E. le Coarer has proposed to perform this detection
in the evanescent field of optical waveguides using superconducting detectors (SSPD) developed by the CEA-
Grenoble/DRFMC. If successful, this still very prospective development would pave the way for a new generation
of ultra small spectrographs that should still have the same efficiency as all other spectral systems known
until now. It would also allow to build spectrograph mosaics rather than bulky 3D spectrographs that are
conventionally developed.
Detectors of this kind would have numerous applications in all fields where very fast spectroscopy is required like
telecommunications, cryptography and medicine. This is the reason why UJF has taken a patent on this topic.
In mid-2006, the studies that already started will show whether the development can be further undertaken.
LAOG will then have to analyze which objective is realistic and to decide what actual effort can be invested
into this direction.
12.3.3 Means and methods
The need for rather large collaborations is especially true for the Lippmann detector development. In the
continuity with successful collaborations with CEA-DRFMC, CRTBT, IMEP and IRAM, and in the context of
the MINALOGIC facilities, at least two new emerging collaborations can be cited to this end:
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• ANR Alterdetect, with IMEP : simultaneous demonstration of Lippmann spectroscopic capability using
Radio then millimetric waves and Near Infrared guided optics.
• ANR Nanodesir, with CEA-DRFMC : The Lippmann effect coupled supraconducting SSPD to generate
a nanosystem achieving photon counting and spectroscopy is one driver to develop research on superconductivity.
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Chapter 13
Recruitment plan
GRIL needs are two-fold: researchers with instrumental skills able to fullfill key responsabilities in large projects
or with research programs in specific technological fields that are at the heart of our R&D projects; engineers with
a strong motivation in R&D activities and expertise in the fields that are of importance for our developments.
Because of the strong commitment the LAOG has towards the VLT Planet Finder realisation and that of
the VLTI 2µm imager, very likely to be scheduled soon, it is essential to increase our resources in some very
specific fields of expertise in order to maintain and consolidate our R&D capabilities. For this reason, during
the next quadrennal period, GRIL should either recruit or welcome external persons on the various profiles
described below according to the two categories, pure instrumental profiles (GRIL recruitments) and mixed
astrophysical-instrumental profiles (thematic team recruitement with participation to GRIL activities).
GRIL profiles
1. Adaptive optics R&D and system
Goal: Increase the LAOG capabilities in AO instrumentation. Because of our major involvement in the
large PF project, most of our capabilities connected to AO expertise will be focused on the realisation
of this instrument. In order to succeed in this whole pursuing our innovative R&D activities in AO, we
need to increase our global capabilities in AO components R&D and/or system definition by recruiting
an AO-oriented instrumentalist researcher accompaning the recruitment of an AO-dedicated project manager/system
engineer (IR1). This should occur in the fall of 2006.
Target: 2007 or 2008
2. Nulling interferometry at thermal IR wavelengths
Goal: Preparation studies for Darwin. In parallel and support to R&D on thermal IR guiding optics,
such as IODA and other possible studies in preparation for DARWIN, we have identified the need for
a researcher strongly dedicated to the search for planets in MIR in general and personally involved in
the preparation of DARWIN or precursor missions. He would have to pilot the preparatory studies that
LAOG is performing and possibly going to enlarge in the frame of its pluriannual commitment to ESA
and ALCATEL ALENIA partnership.
Target: 2007
3. JMMC support for 4-6T exploitation
Goal: Participation to the JMMC developments supporting the VLTI evolution toward more than 3 beams.
LAOG has a special role in the JMMC since it harbors the coordination center and some key members
of the working groups. Because of its probable involvement in a second generation instrument, it should
also help in developing the dedicated tools for the VLTI exploitation.
Target: 2008
It should be noted that these profiles might evolve according to the actual profile of the MdC who should
be recruited in section 34 or any other recruitment possibly achieved in 2006.
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Mixed GRIL-other team profiles
1. Adaptive optics instrumental development
Goal: Increase the LAOG capabilities in AO instrumentation. Because of our major involvement in the
large PF project, we need to increase our capabilities of integration of AO-based instrumentation by
recruiting an astrophysicist with experience in the final tests and performance analysis as well as in the
operation and exploitation of AO imagers. Such a profile, with instrumentation as a secondary motivation
(ideally CNAP ”services d’observation”), should appear both in GRIL and in a thematic team.
Target: 2007 or 2008
2. NIR interferometric spectro-imaging
Goal: Exploitation of the new imaging capabilities of the VLTI. Second generation instruments, such as
VITRUV, will provide unprecedented imaging capabilities to the VLTI. The need is to prepare adequately
the LAOG to the optimized exploitation of this mode by recruting a researcher directly involved in the
VLTI 2nd generation instrumentation realisation. Such a profile, with instrumentation as additional
competence and motivation, could appear both in GRIL and in a thematic team.
Target: 2009
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Chapter 14
Appendix
14.1 Staff
14.1.1 Permanent staff
People involved in the instrumental activities at LAOG over the 2001-2005 period are listed in the table 14.1
below. Some members of GRIL being also active in another team, their other team is also indicated. Those
mostly involved in prospective and/or publishing in instrumental research are in the upper part of the list.
Other are contributors at various levels in the GRIL activities.
14.1.2 PhD students
• Adaptive optics projects: Gael Chauvin (NAOS), Guillaume Montagnier (VLTPF), Jean-François Sauvage
(VLTPF), Wilfrid Schwartz (DM).
• Interferometric projects: Myriam Benisty (IONIC, VITRUV), Carla Gil (AMBER), Pierre Haguenauer
(IONIC, MAII), Oscar Hernandez (AMBER), Lucas Labadie (IODA, IONIC), Emmanuel Laurent (IONIC,
IODA), Jean-Baptiste Le Bouquin (IONIC, VITRUV), Laure Lagny (IONIC), Pierre Mège (AMBER),
Florentin Millour (AMBER), Eric Tatulli (AMBER, JMMC).
14.1.3 Other contributors
• Adaptive optics projects: Amandine Blanc (NAOS, MCAO, 2year CDD), Rodolphe Conan (VLTPF, 3year
post-doctoral fellow), Zoltan Hubert (DM, 1year CDD).
• Interferometric projects: Swain Mark (API, IONIC - Visitor), Guillaume Mella (JMMC, JRA4 - CDD),
Sylvain Cètre (JMMC, JRA4 - CDD), Willem-Jan de Wit (AMBER - postdoc), Emilie Herwats (VIT-
RUV, PEGASE - Master 2 student), Pierre Demolon (IONIC - INSA Rennes student), Fatemeh Zabihian
(IONIC-VLTI - Master Pro Optique student), Pierre Gratier (VITRUV - ENS Lyon student), Bram Acke
(AMBER - external PhD student - Univ. Louvain), Frédéric Rooms (IONIC - external PhD student -
IMEP), Elena Dufour (IODA - ENSI Caen), Coralie Aubert (VITRUV - Master 1 student), Laurianne
Pichon (VITRUV), Axel Chetail (VITRUV), Benoit Neichel (VITRUV).
14.2 Main publications
• NAOS on-line characterization of turbulence parameters and adaptive optics performance, Fusco T., Rousset
G., Rabaud D., Gendron E., Mouillet D., Lacombe F., Zins G., Madec P.-Y., Lagrange A.-M., Charton
J., Rouan D., Hubin N., Ageorges N.; 2004; Journal of Optics A: Pure and Applied Optics; 6; 585-595
139

Name Grade Comm. Project
Berger Jean-Philippe AA FOST IONIC, VITRUV, JMMC
Beuzit Jean-Luc CR FOST MDM, VLTPF, MCAO, WIRCAM
Chalabaev Almas CR FOST GRIF, VLTPF
Charton Julien IR MDM, NAOS, VLTPF
Chelli Alain A FOST AMBER, JMMC, EII
Duvert Gilles AA FOST AMBER, JMMC, EII
Feautrier Philippe IR (HDR) NAOS, WIRCAM, VLTPF
Jocou Laurent AI MDM, IONIC, MAII, IODA, VITRUV
Kern Pierre IR NAOS, MDM, AMBER, IONIC, MAII, IODA, VITRUV, EII
Le Coarer Etienne IR (HDR) AMBER, IONIC, IODA, VITRUV
Malbet Fabien CR FOST AMBER, IONIC, VITRUV, JMMC, PEGASE, EII
Perraut Karine AA AMBER, IONIC, IODA, VITRUV
Perrier Christian A FOST AMBER, MAII, VITRUV, EII, NACO, VLTPF, WIRCAM
Puget Pascal IR (1) NAOS, AMBER, WIRCAM, VLTPF
Rabou Patrick IR NAOS, VLTPF
Stadler Eric IR MDM, NAOS, WIRCAM, VLTPF
Zins Gérard IR AMBER, JMMC, EII
Arezki Brahim IE AMBER, IONIC, MAII, IODA
Delboulbé Alain AI AMBER, IONIC, MAII, IODA, VITRUV, WIRCAM
Delfosse Xavier AA FOST JMMC
Fraix-Burnet Didier CR SHERPAS AMBER
Glück Laurence IE AMBER, JMMC
Lagrange Anne-Marie DR FOST NACO, VLTPF
Monin Jean-Louis PR FOST AMBER
Petrucci Pierre-Olivier CR SHERPAS VITRUV
Preis Olivier IE IONIC, VITRUV
Note: 1 on leave from LAOG mid-2002
Table 14.1: GRIL permanent staff. Those mostly involved in prospective and/or publishing in instrumental
research are in the upper part of the list. Other are contributors at various levels in the GRIL activities. Note
that 2 engineers are qualified to supervised PhDs (french ’HDR’).
• MOEMS pour la correction de surface d’onde en optique adaptative, by Schwartz W., Beuzit J.-L., Kern
P.; 2003 in Microsystèmes opto-électromécaniques, pp. 141-180
• See section on valorisation for results on MMD development (patents submission prevent publication)
• Series ”Integrated optics for astronomical interferometry” in A&A
• Planar integrated optics and astronomical interferometry, Kern, P.; Berger, J.-P.; Haguenauer, P.; Malbet,
F.; Perraut, K.; 2001 ; C. R. Acad. Sci. Paris ; 2 ; 111-124
• First Results with the IOTA3 Imaging Interferometer: The Spectroscopic Binaries lambda Virginis and WR
140, Monnier, J. D.; Traub, W. A.; Schloerb, F. P.; Millan-Gabet, R.; Berger, J.-P.; Pedretti, E.; Carleton,
N. P.; Kraus, S.; Lacasse, M. G.; Brewer, M.; Ragland, S.; Ahearn, A.; Coldwell, C.; Haguenauer, P.; Kern,
P.; Labeye, P.; Lagny, L.; Malbet, F.; Malin, D.; Maymounkov, P.; Morel, S.; Papaliolios, C.; Perraut, K.;
Pearlman, M.; Porro, I. L.; Schanen, I.; Souccar, K.; Torres, G.; Wallace, G.; 2004 ; Astrophysical Journal
Letters ; 602 ; L57-L60
• First observations with an H-band integrated optics beam combiner at the VLTI, Le Bouquin, J. B.;
Rousselet-Perraut, K.; Kern, P.; Malbet, F.; Haguenauer, P.; Kervella, P.; Schanen, I.; Berger, J. P.;
Delboulbe, A.; Arezki, B.; Schöller, M.; 2004 ; Astronomy and Astrophysics ; 424 ; 719-726
• Infrared Imaging of Capella with the IOTA Closure Phase Interferometer, Kraus, S.; Schloerb, F. P.;
Traub, W. A.; Carleton, N. P.; Lacasse, M.; Pearlman, M.; Monnier, J. D.; Millan-Gabet, R.; Berger,
J.-P.; Haguenauer, P.; Perraut, K.; Kern, P.; Malbet, F.; Labeye, P.; 2005 ; The Astronomical Journal,
Volume 130, Issue 1, 246-255
140

• Tantalum superconducting tunnel junctions for infrared photon counting, Jorel, C.; Villégier, J.-C.; Feautrier,
P.; Benoit, A.; 2004 ; Nuclear Instruments and Methods in Physics Research A ; 520 ; 516-518
14.3 Industrial development
14.3.1 Patents
Three applications have been filled regarding possible patents in the frame of our R&D activities on new
deformable micro-mirrors. All three patents have now been issued. Details are given below:
• ”Dispositif d’actionnement électrostatique miniature et installation comprenant de tels dispositifs”, European
Patent, CNRS/CEA, FR0206293 from 23/05/2002. Patent holders: J. Charton and E. Stadler.
• ”Composant MEMS électrostatique permettant un déplacement vertical important”, French patent, CNRS/CEA,
FR0351211 from 26/12/2003. Patent holders: J. Charton and C. Divoux (CEA/LETI).
• ”Miroir déformable magnétique”, French Patent, CNRS, FR0452342 from 12/10/2004. Patent Holders:
J. Charton, Z. Hubert, L. Jocou, E. Stadler, P. Kern and J.-L. Beuzit.
Two applications are currently processed in the frame of our activities on future detectors:
• ”Détecteur et caméra spectroscopique interférentiels”, French Patent, UJF INPI 04/52992, applied December
15th 2004. Patent Holders: le Coarer, E., Benech, P.
• ”Spectrographes à onde contra-propagative”, French Patent, UJF INPI 05/08429, applied August 8th
2005. Patent Holders: le Coarer, E., Benech, P., Blaize, S., Kern, P., Lérondel, G., Morand, A.
14.3.2 Technological transfer
After the commercial license agreements signed for the distribution of our magnetic deformable mirrors, it is
intended to extend this industrial development to other instrumental research results.
14.4 Highlights
The main facts related to our activities since 2001 are summarized below:
• The NAOS (Nasmyth Adaptive Optics System) instrument for the VLT is now offered to the ESO astronomical
community after a successful commissioning and science verification between November 2001 and
August 2002.
• Magnetic Deformable Mirrors are now fully functional and available to all interested parties through our
industrial partners.
• The developments of electrostatic deformable mirrors between LAOG and CEA/LETI is underway with
a first fully functional 19-actuators laboratory prototype being characterized.
• The “Planet Finder” proposal for a second generation instrument for the VLT led by LAOG was selected
by the ESO STC in April 2005 after a successfull 2-year phase A study, awaiting formal decision by the
next ESO Council.
• Development, Integration, Installation of the AMBER instrument to ESO. It is now offered to the ESO
astronomical community for part of its modes and will be fully offered when the VLTI improvement plan
is completed.
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• First fringes in the H band with 3 telescopes of IOTA by means of an integrated optics beam combiner
(Monnier et al. 2004, Kraus et al. 2005)
• Nulling of 10 −4 achieved on the ALCATEL Space MAII bench by using an integrated optics beam combiner
developed under ESA contract.
• First formal demonstration of single mode guiding at 10 µm in the IODA project (Labadie et al. 2005)
• Creation and development of the Centre Jean-Marie Mariotti (JMMC) with partners. Consecutive creation
of the European interferometry Initiative (EII) coupling interferometry networks of the OPTICON EC I3.
• Development, Integration, Installation of the WIRCAM instrument to CFHT. It is now offered to the
CFH community.
14.5 Awards
• The 52-actuator magnetic mirror has won the Photon d’Argent award of the Vitrine de l’innovation (second
most innovative project) during the OPTO 2005 exhibition in September 2005
• Pierre Kern received the Cristal du CNRS in 2005 for the quality and scope of his personal contribution
to a number of R&D as well as large projects
• Fabien Malbet received the COMPAQ/SF2A price in 2004 for his pioneering contribution in long-baseline
near-infrared interferometry and its application to the study of young stars
14.6 Acronyms
• AMBER: near-infrared spectrograph for the VLTI
• ANR Agence nationale de la recherche
• ADONIS AO system installed on the ESO 3.6m telescope
• API Antarctic Planet Interferometer
• ARENA Antarctic Research, a European Network for Astronomy
• AT VLTI auxiliary telescopes
• CEA Atomic studies agency
• CHARA Center for High Angular Resolution Astronomy Array
• CNAP Conseil National des Astronomes et Physiciens
• CNES Centre National d’Etudes Spatiales
• CRTBT Centre de recherche des très basses températures (CNRS)
• MDM: Micro Deformable Mirrors
• DRFMC (CEA) Département de Recherche Fondamentale de la Matière Condensée
• EC European Community
• EII European Interferometry Initiative
• FALCON Fiber-spectrograph with Adaptive optics on Large fields to Correct at Optical and Near-infrared wavelengths
• FLUOR Fiber-Linked Unit for Optical Recombination
• FP Framework Programme (of EC)
• GdR Groupement de recherche (CNRS)
• GeeO : Groupement d’Electromagnétisme Expérimental et d’Optoélectronique - Grenoble
• GENIE Ground-based European Nulling Interferometer Experiment
• GLAO Ground Layer Adaptive Optics
• GTO Guarantee time observing
• HRA High angular resolution
• HARPS High Accuracy Radial velocity Planetary Search
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• I3 IInternational Integrating Infrastructure (of EC FP)
• IMEP Institut de Microélectronique, Electromagnétisme et Photonique (INPG)
• INPG Institut National Polytechnique de Grenoble
• IODA Integrated Optics for DArwin
• IONIC Integrated Optics Near-Infrared Camera
• IOTA Infrared Optical Telescope Array
• JMMC: Jean-Marie Mariotti Center
• JRA Joint research activity
• KEOPS Kiloparsec Explorer for Optical Planet Search
• LETI : Laboratoire d’Electronique de Technologie de l’Information (CEA)
• LGGE Laboratoire de géologie et glaciologie (OSUG)
• LPMC Laboratoire de Physicochimie de la Matière Condensée
• MAII Multi-aperture Imaging Interferometer
• MCAO Multi-Conjugate Adaptive Optics
• NAOS: Nasmyth Adaptive Optics System
• OCA Observatoire de la Côte d’Azur
• ONERA Office national d’étude et recherches aérospatiales
• OSUG Observatoire des sciences de l’Univers de Grenoble
• PdB Plateau de Bure (IRAM interferometer site)
• PNPS Programme National de Physique Stellaire (CNRS)
• STC Scientific and Technical Committee (of ESO)
• STJ Super conducting jonctions
• TGE Very large equipments
• VITRUV: near-infrared imager for the VLTI
• WIRCAM: Wide-field InfraRed CAMera
• XAO EXtreme AO
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144

Part VI
TEAM SHERPA
The two-flow paradigm for compact objets: accretion-ejection solution computed around
a microquasar of M = 10M⊙ and fed with ˙ Macc = 0.01 ˙ MEdd. The color background is the
logarithm of the density (in cm − 3), black solid lines are the field lines and white solid lines
are streamlines. The MHD jet launched from the accretion disc remains mildly relativistic.
Above the black hole, time-dependent pair creation leads to the formation of a ultrarelativistic
beam, maintained warmed and confined by the outer MHD jet. This pair beam
is responsible for both superluminal motions and very high energy emission of compact
objects.
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146

Chapter 15
Results
15.1 History and group composition
In the eigthies, the study of non-thermal phenomena in AGNs was the main research activity of Guy Pelletier,
who came from the plasma physics community. This was essentially the only theoretical work in the laboratory
(Dir. Alain Omont) which, at that time, was originally oriented towards Radio-Astronomy with a focus on the
interstellar medium. This AGN activity then gave birth to a group in the early nineties when Gilles Henri,
coming from the University of Paris XI got a permanent position at the University of Grenoble and when
two brilliant students, Françoise Rosso and Jonathan Ferreira, were hired for a thesis program on Astrophysical
Magnetohydrodynamics (MHD) with G. Pelletier. We thus started a larger activity devoted to accretion-ejection
for both AGNs and Young Stellar Objects (hereafter YSOs) with the students and a new activity devoted to
the High Energy aspect of AGNs with Gilles Henri (the first gamma spectra of some AGNs were about to be
produced by EGRET).
The laboratory was about to increase dramatically with the opening of Infra Red activity and the coming of
a group involved on Young Stellar Objects was under discussion. We were particularly in favor of welcoming this
new component because this was about to open a new field of collaboration in the laboratory and we warmly
supported the arrival of Claude Bertout and his team. Then the laboratory was metamorphosed and our group,
which hired new permanent researchers from Toulouse (Pierre-Yves Longaretti and Didier Fraix-Burnet), took
the name SHERPA (Sources of High Energy Relativistic Plasmas Accretion-ejection). It emphasizes both the
type of objects we deal with, namely sources of high energy powered by accretion-ejection, and the type of
physics we develop, namely, MHD, relativistic plasma physics and transfer of high energy radiation.
Table 1 lists the current permanent staff with their main activity. In 2005, the group hosts Yaël Fuchs
with an ATER position (one year) and three graduate students: Clément Cabanac (started in 2003), Geoffroy
Lesur (started in 2004) and Nicolas Bessolaz (started in 2004, in co-direction with the FOST team). In Fall
2005 a post-doc, Claudio Zanni, will join the group for 2 or 3 years, as well as another PhD student Timothée
Boutelier.
15.2 Specific approach
Among the teams working on MHD astrophysics, high energy cosmic phenomena and the environment of compact
objects, we adopted the following attitude. Instead of running after scoops, we firmly decided to develop
ground researches about the physical issues and the interrelations between the gross phenomena governed by
gravitation and MHD, the kinetic level of relativistic plasmas, including the physics of particle acceleration, and
the physics of the high energy photon emission. Therefore, we are mostly involved in theoretical developments
together with numerical simulations. However, we also provide our expertise by participating in large collaborations
organized for the ”exploitation” of facilities in the whole energy range from millimeter to TeV gamma
range.
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Table 15.1: List of the permanent SHERPA group members in 2005.
Name Grade Specialty
Jonathan Ferreira MdC accretion-ejection, MHD
Didier Fraix-Burnet CR1 astrocladistics
Gilles Henri Prof high energy phenomena
Pierre-Yves Longaretti CR1 MHD instabilities and transport
Guy Pelletier Prof (group leader) relativistic plasma physics, MHD
Pierre-Olivier Petrucci CR2 high energy phenomena
Peggy Varnière CR2 (starting Fall of 2005) MHD simulations
15.3 Accretion-Ejection
15.3.1 The self-similar model
Accretion-ejection phenomena are common-place in astrophysics. They are present in the cores of active galaxies
(AGNs) and quasars but also around compact objects such as X-ray binaries or even some cataclysmic variables
within our galaxy. It is the major physical process governing the growth rate of young stellar objects (YSOs).
Accretion-ejection is therefore a process of major importance. It has long been recognized that the high degree
of collimation exhibited by jets from AGNs or YSOs requires a self-confinement process which can only be
provided by large scale magnetic fields carried in along the jet. This gave rise to MHD models of jet formation
and collimation. On the other hand, all these objects display a correlation between accretion and ejection
observational signatures (Hartigan, Edwards & Ghandour 1995, ApJ, 452, 736). These correlations gave birth
to the idea that accretion and ejection were actually interdependent processes.
Our team was the first to identify the concept of a Magnetized Accretion-Ejection Structure (MAES, Ferreira
& Pelletier 1993, A&A, 276, 625). In such a structure a large scale magnetic field of bipolar topology is
threading the disk. The field exerts a torque which takes away the disk angular momentum thereby allowing it
to accrete towards the central object. A turbulence is needed in order to allow mass to steadily diffuse through
the magnetic field. This angular momentum and energy is then transferred back to a small fraction of the
disk material which gives rise to a self-confined MHD jet. In contrast with other teams, the MAES has been
computed by solving the exact equations of both the disk and the jets: usually, the disk is either ignored (taken
as a mere boundary condition, e.g. Blandford & Payne 1982, MNRAS, 199, 883, Shu et al. 1994, ApJ, 429, 781)
or its vertical structure is crudely approximated (e.g. Wardle & Königl 1993, 410, 218, Li 1995, ApJ, 444, 848).
By taking into account all terms (which was possible thanks to a self-similar ansatz), we were able to provide
the full parameter space of MAES with strong consequences on the level of the required MHD turbulence (Casse
& Ferreira 2000a, A&A, 353, 1115, Casse & Ferreira 2000b, A&A, 361, 1178). This work has been recently
extended by producing the only solutions of jets from accretion disks that cross the three MHD critical points
(Ferreira & Casse 2004).
We are now endowed with the only available model in the literature of disk-driven jets which provides all
fields (density, velocity and magnetic fields) as functions of the disk physical conditions in a consistent way.
15.3.2 Application to different astrophysical contexts
Since jets from YSOs are cooling by optically thin emission lines it is possible to derive strong constraints on
their dynamics and discriminate models. Thus, most past work has been devoted to YSOs. The application of
the MAES model to compact objects is only beginning, with a focus on ”microquasars”.
Young Stellar Objects.
Using the self-similar MAES model, we were able to compute synthetic observations and compare them
to real observations. A previous work done in collaboration with observers (Garcia et al. 2001a, A&A, 377,
589, Garcia et al. 2001b, 377, 609) showed that most of the T-Tauri optical jet properties (line profiles, flux,
jet velocities, evolution of the jet diameter along the distance) could be easily explained by disk-driven jets.
148

Figure 15.1: A standard accretion disk (SAD) fed with ˙ Ma = 0.01LEdd/c 2 is established down to a radius rJ
which marks the transition towards a jet emitting disk (JED), settled down to the last stable orbit. The JED
is driving a mildly relativistic self-collimated electron-proton jet (MAES) which, when suitable conditions are
met, is confining and inner ultra-relativistic electron-positron beam. Field lines are drawn in red solid lines and
the number density is shown in greyscale (log 10 n/m −3 ).
However, observations require a rather large ejection to accretion ratio which can only be attained when there
is some heat deposition at the disk surface layers. This was again confirmed by near-IR modeling of the jet
emission (Pesenti et al. 2003). Finally, when taking into account observational biases in the detection of jet
rotation, disk-driven models with heat deposition are the best candidates (Pesenti et al. 2004, Ferreira et al.
2005, submitted). This work has been done in collaboration with members of the FOST team. Such heat
deposition has to come from local dissipation of the accretion energy, even in the presence of illumination by
stellar UV and X-ray fluxes (Garcia et al. 2005, submitted).
X-ray Binaries.
Microquasars are X-ray binaries where the primary is a black hole, displaying jets with an intriguing time
variability. Indeed, they change their spectral state from a ”High/Soft” (dominated by a soft disk component)
to a ”Low/Hard” (dominated by a hard power-law emission) state on time scales of hours. Jets are only seen
during the Low/Hard state. Moreover, it has been recently shown that this evolution is following an hysteresis
cycle. Therefore, these objects provide valuable clues on the secular evolution of the accretion-ejection process
(their dynamical time scale is the millisecond). Such transitions between spectral states would be unobservable
for AGNs.
Within our framework, a MAES is settled in the innermost disk regions surrounded by a standard accretion
disk as illustrated in Fig. 15.1 (Ferreira et al. 2005). This picture allows to explain several aspects of the
microquasar phenomenology: jet production in the Low/Hard state, jet quenching in the High/Soft state,
superluminal flares (pair plasma) under certain circumstances. Although each spectral state can be explained
by varying the relative importance of each component, several crucial questions remain to be investigated. This
requires a coupling between MHD and high energy physics and is therefore a central theme of our group.
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15.4 Transport phenomena in accretion-ejection flows
The existence of accretion-ejection structures raises a number of prominent issues, which, for most of them,
have been around from the very beginning of this field of research.
15.4.1 Jet stability
The exceptional propagation length of jets, as compared to their radii, raises the question of the physical
mechanisms responsible for their stability. This question has at least two different aspects:
(1) Jet global stability properties. Purely hydrodynamical jets are quickly destroyed due to the development
of the Kelvin-Helmholtz instability. MHD jets seem to be more stable with respect to Kelvin-Helmholtz modes.
However, such MHD jet are prone to be unstable with respect to purely MHD (current- and pressure-driven)
instabilities, the outcome of which is still unknown on theoretical grounds. These instabilities are well-known
to be quite disruptive in the fusion context, so that the very small level of research activity in the astrophysics
community on these issues is all the more surprising.
(2) Particle acceleration. However, one certainly does not want to quench every possible mode of instability
in MHD jets as some turbulence is required to accelerate the non-thermal particle populations which are
responsible for the high energy emission of these objects. In particular, in the framework of the two-flow model
developed by the SHERPA team, it is essential to understand and characterize the processes responsible for the
turbulent stirring of the pair plasma, which tap the energy reservoir of the large scale MHD jet.
In order to make progress on these issues, the effect of pressure- and current-driven instabilities in jets are
examined ab initio. Pressure-driven instabilities are expected to be most disruptive in jets confined by the
hoop-stress, and a linear analysis of the problem has been undertaken (Kersale, Longaretti & Pelletier, 2000,
A&A, 363,1166; Longaretti 2003; Longaretti & Baty in preparation). A complete review of the question of jet
structure and stability, based on both the astrophysical and fusion literature, has also been written (Longaretti
2005).
15.4.2 Transport in accretion disks
The question of mass and angular momentum transport in accretion disks is one of the oldest issues in this branch
of astrophysics, and has not yet been resolved in a satisfying way. In spite of the remarkable progress undergone
in the last fifteen years, with the (re)discovery of the “Magneto-Rotational Instability” (MRI, Balbus & Hawley
1991, ApJ, 376, 214), and the (essentially numerical) characterization of the induced turbulent transport in the
nonlinear regime (e.g. Stone et al. 1996, ApJ, 463, 656), many issues are still acutely open:
(1) Not all disks, or disk regions, are ionized enough to sustain MHD activity (e.g. Gammie 1996, ApJ, 457,
355, Matsumura & Pudritz 2003, ApJ, 598, 645). The transport in these regions must therefore be sustained
through non-MHD mechanisms.
(2) The accretion-ejection structures most actively studied in our group do require a fairly high level of turbulent
resistivity to be self-consistently maintained (Ferreira & Pelletier 1995, A&A, 295, 807). It is unclear
whether the MRI can provide it.
To settle these questions, we have first addressed and completely reinvestigated the old issue of the existence
of subcritical turbulence in keplerian flows. The underlying idea is that all linearly stable flows accessible to
laboratory experiments are observed to undergo a transition to turbulence (called subcritical). The initial
proposal by Shakura & Sunyaev (1973, A&A, 24, 337) was that such a mechanism was at work in keplerian
disks (which are hydrodynamically stable). This picture has given rise to controversial points of view in the
astrophysics literature (Balbus, Hawley & Stone 1996, ApJ, 467, 76; Richard & Zahn 1999, A&A, 347, 734).
Due to the formidable complexity of the problem, little progress had been accomplished on this issue at a
fundamental level, until the last decade, where an interesting breakthrough has been operated in the fluid
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mechanics community, for non-rotating shear flows. Based on this new understanding, the question has been
reinvestigated in rotating flows (such as the keplerian flows), through i/ a phenomenological analysis (Longaretti
2002); ii/ a reinvestigation of all the relevant laboratory experimental data (Longaretti and Dauchot 2005;
Longaretti and Dauchot, in preparation; Dubrulle et al. 2005); and iii/ numerical simulations (Lesur and
Longaretti 2005). This work has lead to the conclusion that a stabilizing rotation does not quench the transition
to turbulence, but nevertheless considerably reduces the efficiency of the subcritical turbulent transport, thereby
settling this old dispute.
Geoffroy Lesur has started a PhD in September 2004, under the supervision of Pierre-Yves Longaretti, with
the aim to investigate in a more systematic way the question of turbulent transport in disks and jets, both from
analytic and numerical points of view.
15.5 Physics of high energy sources
15.5.1 Seyfert galaxies
Seyfert galaxies are strong X-ray emitters with a characteristic X-ray spectra. It is roughly power-law like
above 2 keV, with the presence of a high energy cut-off near 100 keV (e.g. Petrucci et al. 2001, ApJ, 556,
716; Zdziarski et al. 2000, ApJ, 542, 703). Secondary components, like a fluorescent iron line near 6.4 keV
and a bump in the 10-50 keV range are also generally present. The X-ray emission is generally supposed to
be produced by a hot and optically thin thermal plasma (a corona) localized above the accretion disk and
comptonizing the disk photons. The secondary components are thought to result from the Compton reflection
of the X-rays on the disk surface. Due to the lack of sensitivity in the hard X-ray/soft gamma ray energy range
(0.1-1 MeV) of the detectors, the real nature of the high energy continuum of Seyfert galaxies remains unclear.
We have recently tested two different geometries of the disk-corona configuration using the most well adapted
data for the study of the Seyfert high energy continuum i.e. the BeppoSAX 1 brightest Seyfert sample (Petrucci
& Dadina 2005 in preparation). This subsample contains 28 objects. It appears that both geometries agree
with the data but more importantly, we show that the behaviors of the physical parameters of the models
(mainly the temperature and optical depth of the X-ray corona) are strongly geometry dependent, resulting in
completely different physical interpretations. This work is an extension of previous works done on a smaller
sample (Petrucci et al, 2000, ApJ, 540, 131; Petrucci et al. 2001, ApJ, 556, 716) and underlines the weakness
of the actual constraints.
Stronger and less ambiguous constraints on the nature of the coronal plasma can be obtained from variability
studies. For example, thermal models, where hot and cold phases are in radiative equilibrium, predict that the
X-ray spectrum of the sources should harden when the corona temperature increases (Haardt et al. 1997, ApJ,
476, 620) while non-thermal models predict the reverse (Petrucci et al. 2001, A&A, 374, 719). The analysis of
the ∼1 month simultaneous IUE/RXTE monitoring campaign on NGC 7469, performed in 1996, appears to be
in agreement with thermal comptonization emission (Nandra et al. 2000, ApJ, 544, 734). We have performed
a more recent reanalysis of these data with realistic comptonization codes that gives another support to this
interpretation (Petrucci et al. 2004). Missions with X-ray/γ-ray broad band capabilities and higher sensitivity,
like the future ASTROE-2 mission, are required to progress in this field.
On the other hand, the highly sensitive instruments of the XMM-Newton satellite enable very new and
exciting results concerning the fluorescent iron line. Broad iron lines are clearly present in some Seyferts and in
objects like MCG-6-30-15, their broad profiles suggest the presence of spinning black hole, close to the extreme
Kerr value (Fabian et al., 2000, PASP, 112, 1145) and require very steep disk emissivity laws (Wilms et al. 2001,
MNRAS, 328, L27; Fabian et al. 2002, MNRAS, 335, L1), steeper than standard accretion disk one. This is
in agreement with the model we proposed some years ago where the irradiating X-ray source was concentrated
on the disk axis, above the black hole (Henri & Petrucci 1997, A&A, 326, 87; Petrucci & Henri 1997, 326, 99
but see also Martocchia & Matt 1996, A&A, 282, L53; Martocchia et al. 2002, A&A, 383, L23). More recently,
redshifted narrow iron lines have been also observed in an increase number of objects (e.g. Yaqoob et al. 2003,
ApJ, 596, 85; Longinotti et al. 2004; Porquet et al. 2004, A&A, 427, 101; Turner et al. 2004, ApJ, 603, 62;
Iwasawa et al. 2004, MNRAS, 335, 1073). These lines can be interpreted as signatures of small magnetic flares
illuminating small part of the accretion disk. We are investigating the presence of such a line in the Seyfert 1
1 BeppoSAX was an Italian-Dutch satellite covering the 0.1-200 keV energy range. It stopped observing in 2003.
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Figure 15.2: Spectral energy distribution of Markarian 501 during the flaring states of April 7 and 16, 1997,
fitted by a simple time averaged model (Saugé & Henri 2004). Dashed line : simulated spectrum before intrinsic
absorption ; solid line : spectrum after correcting form intrinsic absorption. The grey points are the raw data
from CAT observations, and open squares are the data corrected from extragalactic absorption.
galaxy Mkn 841. In a first XMM observation, we observed a rapidly variable narrow iron line in this source
(Petrucci et al. 2002). Due to the short exposure (2×15 ks), the statistic was not high enough to contrain
the origin of the variability. A new XMM observation, longer (45 ks+25 ks) than the previous one, has been
performed recently (January 2005). Work is in progress to carefully analyse these data and to better determine
the origin of the line variability.
15.5.2 Blazars and the “two-flow” model
A subclass of AGNs is formed by the radio-louds objects, characterized by an intense radio luminosity : they
comprise radio-galaxies and quasars. When imaged through interferometric techniques, the radio emission is
found to arise from powerful jets emitted from the central engine in the galaxy core. The radio emission is highly
polarized and rapidly variable, and is thought to be the result of incoherent synchrotron emission, produced by
non thermal, highly relativistic particles in the presence of magnetic field, emitted in relativistic jets with high
Lorentz factors. The most powerful and variable objects are called blazars. This property is also responsible
for the appearance of superluminal motions at parcec scale, i.e. apparent velocity larger than the velocity of
light, which imply a lower limit on the value of the Lorentz factor, which is usually about 10.
In the early 90s, the development of space gamma-ray astronomy (particularly the CGRO observatory) and
ground based Atmospheric Cerenkov Telescopes (ACT), has revealed that many blazars are also strong gammaray
emitters, the highest energy photons being detected above the TeV energy through ACT like Whipple. A
new generation of ACT is currently growing, the most remarkable and probably best instrument being the HESS
telescopes in Namibia (see international collaborations). Gamma-ray photons, like radio emission, are thought
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to be produced in the relativistic jets, explaining the high luminosity without gamma-gamma absorption.
There are three processes, still discussed, to explain the generation of extragalactic jets : i) the jet launching
by a magnetized accretion disk, ii) the Poynting flux generation by a magnetized spinning Black Hole, iii)
the Compton rocket propulsion in the anisotropic radiation field of an accretion disk (purely hydrodynamical
processes have been discarded). All the three scenarii have problems to account for observations. The first one
turns out to be the most powerful, the most collimating, and able to explain the power input in the FR2 hot
spots, which is a sizable fraction of the accretion power. To be powerful, it requires that the jet extracts most
of the angular momentum of the disk, which, in turn, deeply modifies the accretion regime (uaccr ∼ h/rVkep
instead of h 2 /r 2 VK like in standard accretion disk) and it can be shown that the accretion flow is neither a
SAD nor an ADAF; we call it “JED” for Jet Emitting Disk. But it turns out that this process cannot generate
highly relativistic flow because of its baryon load. The second one is less powerful, has a much less collimating
property and particularly suffers of the efficient Compton drag exerted by the accretion disk radiation field.
The third one leads to a rapid decay when the electron-positron plasma cools by Compton radiation.
A priori there is no reason to assess that only one of these processes is at work. How to avoid the two others?
The general solution is a combination of the three. In order to explain radio observations, Guy Pelletier (1985,
Congr?s de la Soci?t? Fran?aise de Physique) proposed that the jets could harbour a double structure: a strong,
only mildly relativistic jet (v ∼ 0.5c) emitted by the accretion disk, through the MHD mechanism described
Sect. 15.3, and a highly relativistic beam of electron-positron pairs, propagating inside this jet whatever its
production process (Pelletier et al. 1988, Phys Rev A, 38, 2552, Sol et al. 1989, A & A, Pelletier & Roland
1989, A&A, 224, 24, etc.). In a second stage, the model has been more elaborated in order to explain the
discovery of the gamma emission of Blazars. The pair plasma of the relativistic beam is not only channeled
by the MHD jet, but also heated by the MHD turbulence (Henri & Pelletier 1991, ApJ, 383, L7), which
allows the Compton Rocket to work. Only this beam would be responsible for all relativistic phenomena,
superluminal motions and non thermal radio-to-gamma-rays emission (e.g. Marcowith, Pelletier & Henri 1997,
A&A, 323, 271). This ”two-flow” structure solves most theoretical problems associated to the generation of
the jet, explaining for exemple the relativistic motion by an anisotropic Inverse Compton effect (Renaud &
Henri 1998, MNRAS, 300, 1047). We have developed detailed radiative calculations, showing that the non
thermal emission could be very well explained by the model. In the frame of Ludovic Saugé’s thesis, defended
in 2004, we have investigated the influence of the particle energy distribution function (EDF), exploring the
consequences of using a quasi-monoenergetic EDF (more exactly a relativistic quasi-maxwellian, Saugé & Henri
2004) instead of a multi power-law used by most authors. We have shown that such a distribution applies very
well to TeV blazars (Fig. 15.2). We have also developed a full time-dependent model describing the evolution
of the pair plasma coupled with the turbulence. This model is undergoing improvements in order to allow
detailed comparisons with observations (particularly the recent multiwavelength campaigns led by the HESS
collaboration).
This double ejection model has been mostly developed in the environment of Schwarzschild Black Holes.
In the case of a Kerr Black Hole, we expect that the Poynting flux generated pair beam will decay under
usual conditions in AGNs and that only the Compton Rocket would work. However some situations where the
opacity to pair creation would be lower would give more chance to the Blandford-Znajek to contribute. A three
process ejection could even be at work when the opacity condition varies in the nucleus, with Blandford-Znajek
process alternately at work when the opacity is low, the Compton rocket at work when the opacity is high (see
explanations in ”Black Hole induced ejections” GP 2005).
15.5.3 Microquasars
Another class of compact objects is represented by the so-called X-ray binaries, in which a neutron star or a
stellar mass black hole is associated with a normal star in close orbit, accreting matter from its companion. Some
objects have shown phenomena very similar to quasars, exhibiting strong variable radio emission, superluminal
motion, and possibly gamma-ray emission. As they can be considered as reduced version of quasars (the central
object being 10 8 times as light as supermassive AGNs black holes), they are often called ”microquasars”. We
have undertaken the application of our model of relativistic jets to the ejection observed in microquasars, in
connection with a more general scheme (Ferreira et al. 2005). We explain the various states of these objects by a
transition between a standard accretion disk (SAD) and a jet emitting disk (JED). In this frame, the relativistic
ejections could be associated with the explosive formation of dense pair plasma during so-called ”intermediate”
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states, combining a still powerful jet and a luminous accretion disk. In these states, disk photons can be scattered
up to very high energy by non thermal particles from the jet, which would produce enough gamma-ray photons
to trigger pair production. Detailed quantitative calculations are under work.
In another work, with the PhD student Cl?ment Cabanac, we are studying the time behavior of X-ray
binaries observed with the hard X and γ-rays satellite INTEGRAL. We are currently developing numerical
tools to extract the time information from the raw data, especially the presence of quasi-periodic oscillations
(QPO) that have been commonly detected by the RXTE satellite. The origin of these QPO is still disputed
and an important question is their energy spectrum. We are developing in parallel a theoretical model for these
QPO based on an instability at the transition region between the SAD and the JED.
15.6 Relativistic Plasmas and Cosmic Rays
The non-thermal radiation from Black Hole environments is emitted by a relativistic plasma generated in the
jets. Therefore high energy radiation (including TeV gamma rays, cosmic rays and possible neutrinos) is an
important consequence of accretion-ejection flows around Black Holes. These relativistic plasmas are generated
by specific dissipation mechanisms occurring at relativistic shocks and magnetic reconnections that require some
theoretical developments. Moreover the dynamics of these accretion-ejection flows cannot be fully mastered
without a significant understanding of these microphysics processes. Some progress have been recently done in
our team on these topics which are at the forefront of the physics of the so-called ”Astroparticle Science”.
15.6.1 Relativistic plasmas
Relativistic aspect of the accretion-ejection phenomenon.
The issue of the formation of relativistic jets involves three important intricate problems, namely, the crossing
of critical surfaces, collimation and conversion of the Poynting flux into matter-energy flux. These problems
have been addressed in a synthesis that will appear in a collective book organized by R. Blandford and M.
Lyutikov (Pelletier 2005).
A major problem of the physics of accretion disks is the excitation of a turbulence state able to efficiently
transfer the angular momentum of matter in order that it progressively falls on the central Black Hole. In the
nineties, a successful solution has been proposed with the so-called ”Magneto-Rotational Instability”. We have
extended the analysis of the instability to the case of a Kerr Black Hole and found an expected intensification
and a wider window of the instability, that makes it compatible with the intense magnetic field required for
launching jets, despite the stabilizing tendency of its tension effect. The analysis has been presented in the
same chapter as before and will be developed in a forthcoming paper.
Magnetic reconnection in relativistic regime.
Nowadays the process of ”magnetic reconnection” is invoked in order to convert Poynting flux into matter
energy flux and radiation in ultra-relativistic flows. Only very fast reconnection processes can be relevant in this
context. Now standard reconnection processes based on the generalization of the Sweet-Parker scheme are too
slow. New investigations in Tokamaks and space plasma physics revealed a new mechanism that turns out to be
independent on dissipation and fast. We are extending this approach to relativistic plasmas. A fair description
of the phenomenon can be obtained in the frame of an appropriate modification of relativistic MHD for both
baryon loaded plasmas and e + − e − -plasmas. This has been presented in a first publication (Pelletier 2005) and
a paper on relativistic reconnection is to be submitted (Pelletier & Longaretti 2005).
15.6.2 Cosmic Rays
Transport of Cosmic Rays in chaotic magnetic fields.
The properties of the transport of Cosmic Rays in weak turbulence theory are known since the seventies.
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Figure 15.3: The spectrum of cosmic rays at a relativistic shock. This spectrum appears as the envelope of
Fermi cycles (i.e. cosmic rays of large mean free path cross the shock front back and forth several times and gain
energy at each crossing cycle downstream-upstream-downstream), the first corresponding to an amplification of
the cosmic ray energy from its initial value ɛ0 by a factor Γ 2 , and the subsequent ones to an amplification by a
factor 2.
Because we crucially need to know them in the strong turbulence regime, especially in relation with the new
investigations concerning the Ultra-High-Energy Cosmic Rays, we have undergone a systematical study of the
transport, by combining theoretical and semi-analytical approaches with Monte-Carlo numerical simulations
(Casse, Lemoine & Pelletier 2002). We have generalized the result of weak turbulence for the pitch angle diffusion
and for the spatial diffusion along the magnetic field, as a function of the characteristics of the turbulence
spectrum and the particle rigidity. But, as for the transverse diffusion with respect to the mean field, the
behavior is deeply different and controlled by the chaotic aspect of the field lines. Furthermore, the diffusion
at Larmor radii larger than the coherence length of the magnetic field does not stop suddenly, the diffusion
coefficient increases proportionally to the square of the particle energy.
Fermi acceleration in relativistic regime with magnetic fronts and shocks.
The enigma of the existence of Ultra High Energy Cosmic rays can be solved along two different but not
exclusive ways : either by a ”bottom up” scenario where the UHECRs are generated by an acceleration process
in the high energy astrophysical sources, or by a ”top down” scenario where some quantum objects, proposed by
a new physics beyond the standard model of particle physics, decay and produce particles in this energy range.
The Pierre Auger Observatory will soon provide a crucial answer to this question. Indeed we will soon know
whether there exists a particle spectrum beyond the ”GZK limit” (which is the energy threshold beyond which
protons loose energy by producing mesons through collisions with the CMB-photons), revealing a generation of
Cosmic Rays that would not come from extragalactic sources. We have contributed to the ”bottom up” scenario
by studying the relativistic regime of Fermi acceleration, necessary for the Cosmic Rays to reach energies of
order 10 20 eV in the considered sources (AGNs and Gamma-Ray Bursts or GRBs). We have developed the
Fermi acceleration in relativistic regime along two different ways : with relativistic fronts and with relativistic
shocks. When an ensemble of magnetic relativistic fronts propagate with relative speeds that are mildly relativistic,
like in GRBs, the elastic scattering of magnetic fronts generates an efficient Fermi acceleration that
we applied to GRBs (see next paragraph). As for the case of a relativistic shock, Martin Lemoine and G.P.
have developed a combined theoretical and numerical study. The formation of the energy spectrum has been
analyzed confirming a recent analysis proposed by Achterberg and Gallant (1999, MNRAS, 305, L6) and the
time scales of the process have been determined. Reliable laws for the generation of Cosmic Rays in relativistic
flows have therefore been provided (Fig. 15.3).
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Excitation of turbulence by Cosmic Rays upstream a shock and consequences for the transport and the Fermi
acceleration.
The results we obtained on the transport of Cosmic Rays make its dependence on the MHD turbulence
spectrum precise. There exist semi-phenomenological theories of inertial turbulence spectra for common situations
where the turbulence is excited at large scales and then cascades over several decades towards smaller
scales where the dissipation takes place. Moreover the Reynolds numbers in astrophysical media are very large.
However, the turbulence excited upstream astrophysical shocks is of a particular nature. Indeed it is excited
by an instability resulting from the acceleration of Cosmic Rays at the shock and the instability amplifies the
MHD modes over all scales through a resonnant regime (larger scales) and a non-resonnant regime (shorter
scales). We have thus undergone the calculation of the turbulence spectra and the transport coefficients. Then
we examined the consequences of the excitation of MHD turbulence on the energetic balance and the final
spectrum of the Cosmic Rays that is steepened. This theoretical effort was made necessary by the indications
delivered by the new observations of supernovae remnants by Chandra and XMM. Our theory incorporates not
only the newest developments on anisotropic MHD turbulence but also an important effect: the backscattering
of progressive Alfvén modes off sound waves (more precisely the slow magneto-sonic waves). These studies have
been realized with Martin Lemoine, Alexandre Marcowith (CESR) and G.P. (in course of publication).
High energy emission and Cosmic Rays from Gamma-Ray Bursts
Gamma-Ray Bursts (GRBs) are phenomena radiating as much energy as supernovae but in a very short
time, a few seconds or even less. The collimation of the ultra relativistic flows involved in GRBs strongly
amplifies the energy flux. Under the less favorable hypothesis about the magnetic field and its irregularities, it
has been shown that Cosmic Rays undergoing scattering off relativistic magnetized fronts (revealed by the light
curves) could indeed reach the UHE range (Gialis & Pelletier 2004). The performances of GRBs as sources of
high energy radiation in the form of photons and neutrinos have been estimated (Gialis & Pelletier 2005). A
gamma diagnosis of UHECR generation is proposed; the diagnosis in the range of a few tens of GeV appears
to be non-ambiguous, because this signal of hadronic origin should not be contaminated by inverse Compton
emission by electrons which is deeply in the Klein-Nishina regime. We are eagerly waiting for the observations
of GRBs by GLAST that could make this diagnosis.
15.7 Heavy numerical simulations
The field of theoretical astrophysical dynamics has undergone two major evolutions in the last two decades or
so. First, the idea that magnetic fields play a key role has progressively imposed itself to a community in which
MHD phenomena had long been regarded as exotic. Secondly, the progressive rise of powerful numerical tools
(both software and hardware) has transformed numerical simulations from a gadget to a must in the exploration
and understanding of the nonlinear outcome of the physical processes considered as important in our trade.
Consequently, MHD has become the central area of study of accretion-ejection related phenomena, and the
modern dynamicist working in this field must not only master analytical techniques, but numerical ones as well.
To a lesser but growing extent, a similar evolution can be witnessed in the field of high energy astrophysical
processes, which is also of direct interest for the team activity.
The French community is still largely lagging behind the international leadership on the numerical front, by
lack of both human and material means (despite the information made by the ASSNA). The SHERPA team
has become more and more aware of this deficiency for its own activity, and has therefore put a particular
emphasis on numerics by progressively building up an internal expertise, and by defining as a goal to address
an evergrowing fraction of problems through (M)HD simulations (in support of more theoretical analyzes). In
practice, this numerical activity is only now reaching a production stage, and has been undertaken in several
directions:
i- (M)HD stability and turbulent transport in disks and jets with Geoffroy Lesur (PhD started september
2004) and P.-Y. Longaretti.
ii- 2D magnetospheric star/disk interaction with Nicolas Bessolaz (PhD started november 2004) and J.
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Ferreira, in collaboration with Rony Keppens (Netherlands) and J. Bouvier (FOST). The goals are to study
first, the conditions leading to steady accretion funnels and second, the possibility to launch Reconnection
X-winds as envisioned by Ferreira, Pelletier & Appl (2000, MNRAS, 312, 387).
iii- 3D magnetospheric star/disk interaction with Claudio Zanni (post-doc starting Fall 2005) and J. Ferreira,
in collaboration with Christian Fendt (Germany). C. Zanni will study the oblique rotator and try to relate the
dynamical situation computed with current observational works carried out by the FOST team (C. Dougados,
J. Bouvier and F. Ménard).
15.8 Astrocladistics
Imagined by Didier Fraix-Burnet in 2001, astrocladistics is a brand new approach toward establishing an evolutionary
history of galaxies, from which a new classification might be devised. This methodology, borrowed
from phylogenetic systematics, a branch of evolutionary biology, is built on the original idea that galaxy diversity,
generated by their evolution, in particular through interactions, could be organized in a hierarchical
manner. In a similar way as for living organisms, Didier Fraix-Burnet and two biologists (Philippe Choler and
Emmanuel Douzery) have proposed to depict ”parenthood” between galaxy classes on hierarchical trees called
cladograms. The underlying notion of complexity for galaxies is thus introduced in extragalactic astrophysics.
Up to now, astrocladistics has been successfully used for the first time on a sample of Dwarf Galaxies from the
Local Group, then on two samples of simulated galaxies (GALICS database of Bruno Guiderdoni et al., stage
de DEA of Anne Verhamme), and currently on samples of galaxies from the Virgo cluster in collaboration with
Emmanuel Davoust from the Laboratoire d’Astrophysique de Toulouse. We now understand how the few hundreds
of galaxies in our samples could have evolved and how much they ”resemble” each other and why. All this
work has been orally presented at two international conferences (Fraix-Burnet et al 2003, Fraix-Burnet 2004),
three papers have been submitted (two of which are now accepted) and two others are being written. Cladistics
is probably unusual and may be even somewhat revolutionary for astrophysicists, but it is clear today that it
brings several concepts and a formalism of major interest for the contemporaneous extragalactic astrophysics.
15.9 Participation in large collaborations
The SHERPA team has strong involvements in several big international projects: the ”JETSET” european
network, several instrumental collaborations (AMBER, VITRUV, SIMBOL-X, GLAST, ECLAIRS) and the
large HESS international collaboration. Moreover, it has strong links with the GdR PCHE and the national
programs PNPS and PNG.
Instruments in which LAOG is involved :
• AMBER: Didier Fraix-Burnet is a member of the Science Group and is PI or coI of several Guaranteed
Time proposals on AGNs.
• VITRUV: P.-O. Petrucci and G. Henri are members of the Science Group of this second generation
instrument for the VLTI.
Other instruments and projects :
• JETSET is an european ”Marie Curie” Research and Training Network gathering 11 european laboratories
which has officially began the 1st of february 2005 and will run four years (http://www.jetsets.org).
J. Ferreira is sharing with S. Massaglia (Italy) the management of the Work Program ”MHD models of
Jets and Outflows”.
• SIMBOL-X: P-.O. Petrucci is member of the Science Group of this hard X-ray (0.5-70 keV) instrument
that should be launched around 2010.
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Table 15.2: Former PhD students of the SHERPA group.
Name PhD thesis Current position
Françoise Rosso 1994 teacher (classes préparatoires)
Jonathan Ferreira 1994 assistant professor in the group
Alexandre Marcowith 1996 CNRS position at CESR-Toulouse
Pierre-Olivier Petrucci 1998 CNRS position in the group
Nicolas Renaud 1999 teacher (classes préparatoires)
Evy Kersalé 2000 postdoctoral position at Leeds-Cambridge
Fabien Casse 2001 assistant professor at Paris VII
Denis Gialis 2004 engineer at ONERA
Ludovic Saugé 2004 postdoctoral position at IPN-Lyon
• GLAST: the whole team is involved in the scientific support. With an overlap with the HESS window,
this mission should provide invaluable clues on compact objects and GRBs.
• ECLAIRS: G. Henri and G. Pelletier are involved in the scientific support of this instrument with the
goal of studying the prompt emission of GRBs.
• HESS: G. Henri, G. Pelletier, P.-O. Petrucci are deeply involved in the HESS collaboration where they
provide a scientific support, especially for the interpretation of Blazar observations and multi-wavelength
approaches. This Astroparticle experiment is very successful (cf. papers in Nature, Science...) and is
opening a new window of astrophysics.
15.10 Doctoral formation and Schools
The SHERPA team is heavily involved in teaching activities through the presence of 3 teachers (out of 6
permanent members), including 2 professors who have benefitted from a position at the prestigious Institut
Universitaire de France. One of them, G. Henri, is the current director for the ”Master 2 Recherche Astrophysique
et Milieux Dilués”, which is the pre-doctoral year before French thesis.
The group has regularly formed PhD thesis students who found good academic or industrial positions for
most of them (see Table 2).
Members of the team have also organized schools for researchers. G. Henri, G. Pelletier and F. Ménard
(FOST) organized a school on ”Accretion disks, jets and high-energy phenomena in astrophysics” in 2002 at
Les Houches. A JETSET school on ”MHD jet models and constraints”, to be held January 2006, is organized
by J. Ferreira and C. Dougados (FOST).
15.11 Scientific Highlights (2002-2005)
• ”Transport of cosmic rays in chaotic magnetic fields”, Casse Fabien, Lemoine Martin, Pelletier Guy, 2002,
Phys. Rev. D.
The knowledge of the diffusion coefficients of cosmic rays is crucial for astrophysical applications and
especially for astroparticle physics, both for mastering the cosmic ray propagation and the efficiency
of Fermi acceleration. They have been computed with a Monte Carlo simulation as a function of the
cosmic ray rigidity and the spectrum of the magnetic field (characterized by its index and its degree of
irregularities). The Bohm scaling, often assumed in astroparticle physics in the strong turbulence regime,
has been ruled out. The scalings derived for the pitch angle diffusion and for the parallel diffusion with
the ”quasi-linear theory” are extended in an appropriate way in the strong turbulence regime. However
the transverse diffusion coefficient follows a law which is nor Bohm nor quasi-linear, but a law that stems
from the analysis of the spatial chaos of field lines. This result is important to estimate the confinement
time of cosmic-rays in galaxies and in extragalactic jets.
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• “Particle Transport in Tangled Magnetic Fields and Fermi Acceleration at Relativistic Shocks”, Lemoine
Martin, Pelletier Guy, 2003, ApJ, 589L.
In Monte Carlo simulations, test particle trajectories are followed in a magnetic scattering medium in
which a plane is moving at subrelativistic or relativistic speed. The conditional probabilities for a particle
to come back to the plane after crossing as a function of the pitch angles have been computed. Then
the amplification of the particle energy at each Fermi cycle (downstream-upstream-downstream) across a
shock is calculated for arbitrary value of the shock speed. Thus the formation of the cosmic ray spectrum
at a relativistic shock is derived and the result displays that the first Fermi cycle produces a strong energy
amplification by a factor on the order of the shock Lorentz factor to the square, whereas the other cycles
amplify by a factor 2, as predicted by Achterberg and Gallant. The index is computed as a function of
the shock Lorentz factor and the results are in excellent agreement with an analytical formula. A precise
law for the acceleration time have also been obtained.
• “Stationary Accretion Disks Launching Super-fast-magnetosonic Magnetohydrodynamic Jets”, Ferreira
J., Casse F. 2004, ApJ, 601, L139
This is the last paper in the series on Magnetized Accretion-Ejection Structures (MAES), which represents
the only available self-consistent model of a self-confined jet driven by an accretion disk (with the disk
fully resolved), able to cross all three MHD critical points. Biases induced by the self-similarity contraints
are discussed.
• ”Physical interpretation of the NGC 7469 UV/X-ray variability”, Petrucci, P. O., Maraschi, L., Haardt,
F., & Nandra, K. 2004, A&A, 413, 477
Data fits, with a detailed model of comptonized spectra obtained from simultaneous UV and X observations
of a Seyfert galaxy. These fits not only reproduce the spectral shape, but the source variability as well.
They allow us to show that the data are consistent with a model where all the accretion power is liberated
in the corona (producing X-rays), while the UV emission comes from the reprocessing of the X-ray flow
rather than from the energy dissipation in the disk. The observed variability is produced by a geometric
modification of the corona.
• “Astrocladistics: a phylogenetic analysis of galaxy evolution. I. Character evolutions and galaxy histories”,
D. Fraix-Burnet, P. Choler, E. Douzery, A. Verhamme. 2005, accepted in Journal of Classification.
This is a first paper in series; the method of astrocladistics is described. It should allow us to establish a
galaxy classificatoin based on physical criteria besides the galaxy morphology.
• “On the Relevance of Subcritical Turbulence to Accretion Disk Transport”, Lesur, G., and Longaretti,
P.-Y. 2005, accepted in A&A
This paper solves a riddle dating back to the seventies, and which has given rise to an important controversy
in the last ten years. Namely, it is shown that a linearly stable, keplerian hydrodynamic flow is indeed
turbulent through non linear mechanisms, but that this turbulence has a low efficiency in terms of angular
momentum transport, with a Shakura-Sunyaev parameter α < 10 −5 . The discrepancy between numerical
simulations and laboratory experiments is explained away.
• ”The bulk Lorentz factor crisis of TeV Blazars: evidence for an inhomogeneous pile-up energy distribution”,
Gilles Henri & Ludovic Saugé, 2005, accepted in ApJ
It is shown that the Lorentz factors of Blazar jets, deduced from homogeneous SSC models, are contradicted
by the source statisticsn which implies Lorentz factors of order 3, whereas homogeneous models
require 50 or more. The only way out of this conundrum is to take the jet stratification into account,
so that high energy photons are not produced in the same region as low energy ones. Observations then
require mono-energetic distribution functions whereas most models make use of power-law distributions.
In contradistinction with the dominant view, this work shows that (1) jets do not need to be highly relativistic,
and (2) turbulence rather than shocks is at the origin of the production of high energy particles.
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Chapter 16
Perspectives
The distinctive feature of our group lies in its focus on physical processes rather than on specific astrophysical
objects. This emphasis has proven to be very fruitful: it allows to make progress on problems that appear in very
different astrophysical contexts (e.g. turbulence in accretion disks, accretion-ejection, non-thermal radiation
from jets) as it relies on the strong theoretical background required to correctly interpret and understand
observations. This last goal is mainly achieved through collaborations with the FOST team and international
observational groups. We want therefore to maintain this specificity within the LAOG.
However, our common interest in specific processes, namely MHD flows (laminar and turbulent), anomalous
transport, kinetic particle acceleration and high energy radiative processes, naturally pinpoints to one astrophysical
context best suited for the development and testing of our theories. Our future activity will thus be
mainly devoted to the understanding of the physics of Black Hole environments.
The study of MHD accretion-ejection flows around a central object will follow two distinct directions. The
first one is the analysis of the timing properties of compact objects : quasars and microquasars. As said
previously, X-ray binaries provide the best available constraints on the time evolution of accretion-ejection
structures. This aspect involves first a strong collaboration between several members of our group. Indeed,
within our ”two-flow” paradigm, flares are produced by a catastrophic pair creation that must have a feedback
on the surrounding MHD jet. One long term goal is therefore to couple pair plasma creation and dynamics
with MHD. The understanding of these phenomena will then be extended to AGNs which exhibit also strong
variability. The hiring of a young scientist involved in this difficult topic would be very valuable to reinforce
this theoretical activity.
The second direction of study is the investigation of the magnetic interaction between a magnetized central
object and its accretion disk, with a focus on angular momentum transfer. This topic is naturally building
strong links with the FOST team. The best observationally studied objects are the young stars but our work
will also apply to cataclysmic variables and some neutron stars. Numerical simulations are most likely the only
efficient tool to attack this critical problem. This work has already begun with one PhD thesis (N. Bessolaz)
and a JETSET post-doc (C. Zanni) and will definitely be continued by using the most recent available codes.
The recent recruitment of P. Varnière within our group and her strong implication in the development of the
MHD version of the AstroBear code is an invaluable input. Although a simultaneous treatment of both the
local and global physics is still out of reach of the current large scale computer resources, we nevertheless hope
to incorporate future results from MHD local analyzes as sub-grid constraints. On the longer term, we will
simulate the environment of a rotating black hole, surrounded by an accretion-ejection structure.
The issue of turbulent transport in accretion disks is of major importance in astrophysics, with several open
issues and controversies. One of them, the role of hydrodynamic nonlinear instabilities, has recently been resolved
by our group, implying that purely hydrodynamic turbulent transport is most likely too inefficient. The
source of transport therefore lies either in (magneto)hydrodynamic, 2D, wavelike structures, or in a local MHD
instability driving turbulence, such as the magneto-rotational instability. In the latter case, the main difficulty
and unsolved problem is the role of magnetic reconnection on the overall efficiency of the induced turbulent
transport. No study has yet tackled this crucial issue, although numerical reconnection most probably largely
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controls the level of the anomalous transport observed in simulations. We plan to address the role of reconnection
(non-relativistic and relativistic) in turbulent transport by means of numerical simulations in the Hall-MHD
framework, following recent advances in the fusion context on this topic. This is a fundamental work that will
have quite universal applications. Of course, this is a very difficult branch of numerical physics requiring more
manpower than that currently available in the group, considering international standards. Therefore, hiring a
young researcher with a large expertise in both theoretical and numerical MHD is of primary importance in the
mid-term, to keep up with international competition.
Astrocladistics is now on the trails and two kinds of directions will be followed in parallel. The first one
is the extension of its application to many more galaxies in the Universe. For instance, the integration of the
Active Galactic Nuclei properties is a necessary and challenging task. In addition, with people in Toulouse, we
are exploring higher redshift objects using big surveys in the making, like the Sloan Digital Sky Survey (SDSS).
After this work (2006) we will strongly connect ourselves to the Virtual Observatory project which will probably
be the ideal data base to feed astrocladistics analyses. The second direction of work is on the theoretical side,
particularly in collaboration with mathematicians in cladistics (statistics, classification, complexity), but also
of course with astrophysicists specialized in galaxy physics and chemistry (interactions, stellar components,
interstellar medium, gas and dust, etc...), as well as in cosmology (the very first objects of the Universe). A new
taxonomy for galaxy classification will be proposed during the next few years (2007). It must be noted that
cladistic analyses are heavily CPU demanding, and clusters and even grids of PCs are necessary to perform the
calculations. A thesis subject (astrophysics) and a post-doc profile (cladistics/mathematics) will be proposed
in 2006.
Although mainly devoted to theoretical works, the SHERPA group has also been involved in many instrumental
collaborations, and intends to strengthen and develop this part of its activity, in the near, mid and long
term projects. In the near future, it will actively initiate or collaborate to observing proposals with existing
instruments : XMM, INTEGRAL, HESS. XMM and INTEGRAL are particularly valuable to study the high
energy emission of compact objects, due to their excellent collection area, allowing fast temporal studies. The
group has initiated in particular a new method to search for rapid QPOs in INTEGRAL data, allowing to
extend their study at high energy (above 20 keV). Thanks to RXTE observations, these QPOs are well known
to exist in galactic compact objects (X-ray binaries and micro quasars) at lower energy, but their spectrum
is poorly known. A progress in this field could bring very strong constraints on the mechanism responsible
for these oscillations, which is still a matter on intense debate. The new analysis technique should be used in
the next years to study archival data and initiate new proposals. The combination of XMM and INTEGRAL
observations is also very valuable, and one of us (P.O. Petrucci) has already strong experience in this type of
proposals. The collaboration with HESS, which the group is officially associated with, will of course continue.
The rapid growth of detected blazars will provide numerous data of good quality, allowing detailed comparisons
with time dependant simulations which have been developed in the group and will be improved in the next
future by the inclusion of a better description of acceleration mechanisms (T. Boutelier’s thesis, starting in
october 2005). Of course, the active participation to HESS shifts will go further.
On a longer term, improvements of the existing instruments as well as the launching of new ones is expected.
The HESS 2 project will increase significantly the collection area of the instrument, allowing a better sensitivity
and the detection of new objects, particularly TeV blazars. A very important application is the indirect
measurement of Cosmic Infra Red Background (CIRB), which absorbs the TeV photons and increases the
spectral index of a distant source. Another exciting discovery is the possible measurement of TeV emission
from a micro-quasar, which would confirm the link between the physics of galactic black holes and extragalactic
ones. The launching of GLAST, planned in 2007, is likely to open a new era in gamma-ray astronomy. Its
unprecedented sensitivity will allow to study a very large number of galactic and extragalactic objects in tha
gamma ray range, bridging the current gap between INTEGRAL (below 1 MeV) and Atmospheric Cerenkov
Telescopes (above 100 GeV). G. Pelletier and G. Henri are officially associated to the project as scientists.
However, because of their teaching duties, the group will need to hire a new young researcher in order to
maintain the reactivity demanded by the scientific support of High Energy facilities (like HESS and GLAST).
Because of its scientific position, the SHERPA group is also involved in two important intrumental projects
that should be operative in the next decade. The first one is the SIMBOL-X hard X-ray mission, operating in
the ∼0.5-70 keV range and with two orders of magnitude improvement in angular resolution and sensitivity,
which is proposed by a consortium of European laboratories (PI: P. Ferrando from Saclay). This will allow to
elucidate outstanding questions in high energy astrophysics, related in particular to the physics of accretion
onto compact objects, to the acceleration of particles to the highest energies, and to the nature of the Cosmic X-
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Ray background. The second project is VITRUV, a second generation VLTI instrument for aperture synthesis
imaging with eight telescopes (PI: F. Malbet from LAOG). VITRUV will permit to obtain completely new
results in a large numbers of astrophysical domains and in particular compact objects. Both projects are in
a R&D level and we (mainly P.O. Petrucci and G. Henri) participate, since the beginning, to the scientific
specification of both instruments.
Other new developments will come from the contact with all the astroparticle facilities such as Pierre Auger
Observatory, Neutrino Observatory (NET Cube), Gravitational Wave Observatories (VIRGO, LISA). Within
10 to 15 years, we can reasonably expect that fascinating astrophysics developments will stem from correlating
gamma-rays, neutrino and gravitational bursts from Black Hole environments. The AGNs containing double
quasars are the most promising sources of gravitational waves for LISA.
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Part VII
APPENDICES
163

164

Chapter 17
Appendix 1: General organization of
LAOG
17.1 Management structure
The present management structure of LAOG has two levels, the Executive Committee [Comité de Direction]
and the Advisory Board [Conseil de Laboratoire]. Their respective roles and composition are in part defined
by legal texts. They are detailed in the LAOG internal by-laws [Règlement Intérieur], which were written
after elaborate internal discussions involving the Advisory Board and an ad hoc working group, and have been
officially approved by CNRS in 2005.
In brief, the LAOG management structure is the following:
Executive Committee
The Executive Committe is in charge of running LAOG in all its aspects (scientific activities, human resources,
administration and financial matters, safety, etc.). It meets on a weekly basis. Its composition (see the general
organigram in Figure 1.3) of the Executive Summary is as follows.
• Director (C. Perrier until Dec. 31, 2002, T. Montmerle thereafter)
• Deputy Director (P.-Y. Longaretti until Aug. 30, 2003, J.-L. Monin thereafter)
• Technical Director (P. Kern, since Sep. 30, 2002)
• Head of Administration (F. Bouillet)
• Computing Resources Manager (G. Duvert)
Advisory Board
The Advisory Board is composed of elected members and members nominated by the Director. Its composition
reflects all personnel categories of LAOG. The key structure of LAOG (i.e., the four scientific teams and the
technical group) is also represented. PhD students have two representaives, elected every year.
The Advisory Board meets regularly, on average every two or three months, more often if necessary. Usual
topics are: general organization, implications of scientific decisions, priorities in hiring young researchers on
permanent positions (in general, temporary collaborators like post-docs and visitors are selected after discussions
between the four team leaders only), or any topic of general interest as proposed by any LAOG member. PhD
student representatives do not participate in the discussions about priorities in hiring young researchers, but
they participate in all the other meetings.
In addition to the Director and Deputy Director, the current list of members is as follows.
• Elected members
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– Ceccarelli Cecilia (AT)
– Delfosse Xavier (AA)
– Ferreira Jonathan (MC)
– Malbet Fabien (CR)
– Ménard François (CR)
– Delboulbé Alain (IE)
– Preis Olivier (IE)
– Stadler Eric (IR)
• Nominated members
– Chelli Alain (AT)
– Beust Hervé (AA)
– Lefloch Bertrand (CR)
– Bouillet Françoise (IE)
– Freautrier Philippe (IR)
– Kern Pierre (IR)
17.2 Management tools and quality control
In order to project an attractive image of its activities, LAOG has invested in refurbishing its web site:
http://www-laog.obs.ujf-grenoble.fr through which all the main documents can be accessed, either publicly
or internally. The activities of the teams are publicly available and regularly presented. A highlight window
in the home page allows to directly browse through recent major results of LAOG, several of which having been
the subject of press releases by our agencies (mainly CNRS and ESO).
Also available via the LAOG web page is Symastro, an internal management system through which various
documents (including instrumental projects), reports, minutes of meetings, electronic forms (orders, missions),
etc., can be accessed using quality-control rules. Among the new documents is the “Règlement Intérieur” (LAOG
by-laws), which regulates many aspects of the everyday life at LAOG (safety recommendations, working hours,
composition of internal councils, etc.).
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Chapter 18
Appendix 2: LAOG Technical group &
facilities
18.1 Introduction
The organization LAOG technical group is driven by the necessity to support efficiently the activity of the
astrophysical teams, mainly dedicated on three points:
• general support to the laboratory (computing support);
• R&D actions dedicated to the preparation of future operations;
• direct involvements in the realization of large instruments dedicated to large international facilities and
agencies (VLT-ESO, ESA, CNES, CFHT).
The main drivers are the critical astrophysical requirements, which are mostly related to High Angular
Resolution (HAR) observations for the two last above items.
18.2 Teams
The composition of the technical group aimes at having the full range of required specialties for all design studies
of very specific instrument dedicated to HAR observations, either through adaptive optics or interferometry
(mechanics, optics, electronics, instrument control, system engineering, project management, and software
development). An important part of the staff, 21 engineers and technicians, has a strong expertise for the
design of the instruments main critical aspects.
The technical group is thus organized into 5 teams (see organigram in Figure 1.3 )
1. Instrumentation, including optics, tests and system expertise
2. Electronics, including design, cabling, and system expertise
3. Mechanics, with strong expertise in CAO, detailed design, finite element analysis, MEMS/MOEMS design
4. General support to the computing LAOG facilities
5. Software developments for all instrumental projects.
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Among the various areas of expertise, very specific competences are available at LAOG, mainly related
to micro-technologies. One concerns fiber optics and integrated optics conditioning, testing and operation for
interferometry. The other one concerns adaptive optics mirror design and building.
An important part of the software development activity, oriented towards interferometry users, is related to
the JMMC (Jean-Marie Mariotti Center, see GRIL chapter and next Appendix).
18.3 Equipment
The LAOG building contains specific facilities for technical developments and instrument integration activities.
• Machine shop with required machining and metrology tools.
• Working stations for CAO (mechanical design and finite element analysis together with related printing
capabilities, thermal simulation, electronic design, optical design).
• An optical lab dedicated to all Interferometry / Integrated Optics developments. It includes:
– facilities for guided optics characterization and connectorization.
– An anti-vibration bench devoted to interferometric measurements related to the image reconstruction
issues connected to the VITRUV developments,
– An anti-vibration bench devoted to interferometric measurements related to thermal IR wave guide
characterization.
• A small clean room for detector integrations, and micro-optics mounting.
• An optical lab for adaptive optics developments, mainly for various Micro Deformable Mirrors characterization.
• An electronic lab with all required tools
• A 200 m 2 , 8-m high integration hall with related facilities (handling, fluid distribution capabilities, control
rooms)
• Vacuum room with all related equipment, including Helium leak detector
• Specific metrology equipments for component and instrument qualification (Wavefront Sensor , electronic
auto pointing collimators, optical and mechanical displacement sensors)
• Specific sources and detectors for near and thermal infrared operations, and photometric characterization.
Oncoming activities will require a significant evolution of the existing technical support. Due to the increasing
range of activities but also to professional evolutions, it is already necessary to hire new engineers and
technicians, specialists of adaptive optics system, of mechanical design and of software development. It is also
mandatory to improve the LAOG experimental integration facilities, especially to be able to achieve the VLT-PF
and possibly VITRUV, integration phases in state-of-the-art conditions. One of the major foreseen improvements
is the environmental control of the integration hall and of the optical lab. The strong constrains that
apply to these sophisticated instruments are a major issue in order to meet the expected severe requirements.
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Chapter 19
Appendix 3: International and Local &
National responsibilities of LAOG
members
19.1 Responsabilités individuelles internationales
19.1.1 Astromol
Ceccarelli Cecilia Co-Astronomer du Consortium Heterodyne Instrument for the Far Infrared (HIFI), a bord
du satellite ESA Herschel Space Observatory (HSO) (2000-2006)
Coordinator du Group “HSO-HIFI Star Formation” (2001-2006)
PI du Key Program HSO-HIFI “Line Surveys of Star Forming Regions” (2005-2006)
Task Manager de “Chemistry in Star Formation” du resau EC FP6 “The Molecular Universe” (2005-2006)
Kahane Claudine
Présidente de la commission d’évaluation de lÕenseignement de la Physique dans les Universites belges francophones
(jan 2003 - mai 2003).
Montmerle Thierry
Membre du Comité des Programmes des satellites XMM (ESA, 2005) et Chandra (NASA, 2002-2003)
Membre du Comité des Programmes de l’ESO, Président du Panel ”Star Formation” (2002-2005)
Valiron Pierre
Membre de l’Advisory Board de la revue Chemical Physics (-2006)
19.1.2 FOST
Jean-Charles Augereau:
- membres des groupes scientifiques des instruments VLT/PF et VLTI/ApreS-MIDI
Jérôme Bouvier:
(2000-2004): CEE FP5 RTN (Clusters): Grenoble + 6 CEE institutes, co-PI
(2002-2003): Key Program CFHT, 2002-2003 CFHT12K/MEGACAM, PI
(2005-2006): ECO-NET 2005 : Grenoble-Tashkent-Moscou, PI
(2001-2002): Membre extérieur du TAC du Telescopio Nazionale Galileo, Italie
(2001): Membre Steering Committee CFHT-WIRCAM
(2004): Membre du Groupe Scientifique CFHT-ESPADONS
Catherine Dougados:
(2005-2008): CEE FP6 RTN (JETSET): Grenoble + 10 CEE institutes, co-PI, Membre du comité exécutif de
JETSET (resp. du training et du suivi des étudiants)
Gilles Duvert:
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-responsable du groupe ”logiciel de traitement des données AMBER”
-Principal investigator du Work Package No2 du JRA4 du Reseau Europeen Opticon (OPTICON, WP2 JRA4)
Nicolas Grosso:
(2004): Membre du Target Allocation Committee de XMM-Newton pour l’ESA (A04)
Fabien Malbet:
(2001-présent): Membre du VLTI Science Demonstration Time
(2001-2003): Membre du comité ad-hoc du VLTI Implementation Committee en charge de la prospective VLTI
2005-2015
- Project Scientist de l’instrument AMBER de L’ESO
François Ménard:
(2003-présent): membre du groupe scientifique du projet d’instrument VLT-PF de l’ESO
Jean-Louis Monin:
(2001-présent): membre du groupe scientifique de l’instrument AMBER
19.1.3 GRIL
Beuzit Jean-Luc
Science Advisory Committee (SAC) du CFHT de 2000 a 2005
responsable scientifique du JRA1 Opticon
Chelli Alain
5/ Coordinateur du JRA4 d’Opticon (”Integrating Interferometry into Mainstream Astronomy”)
6/ Membre du bureau de l’Euro-Interferometry Initiative (EII)
7/ Membre du bureau d’Opticon (ca ce n’est pas tres clair)
8/ Responsable pour la partie francaise du projet ECOS M03U01 de collaboration avec le Mexique, Universite
de Puebla (Interferometrie et Optique Adaptative)
Duvert Gilles
PI WP2 du JRA4
Feautrier Philippe
responsable du JRA2 dans le réseau Opticon
Kern Pierre
Membre du réseau Key Technologies de Opticon (préparation du FP6 et FP7)
Le Coarer Etienne
ELT design Studies (OPTICON) : EPICS
Malbet Fabien
Membre du VLTI Science Demonstration Time (2001-)
Membre du comité ad-hoc du VLTI Implementation Committee en charge de la prospective VLTI 2005-2015
(2001-2003)
EuroWinter School, ”Observing with the VLTI” (mariotti.fr/obsvlti), Les Houches, 3-8 fevrier 2002
JENAM’2002 workshop ”The VLTI Challenges for the Future”, Porto, 5-7 septembre 2002
Perrier Christian
terminé :
Représentant francais à l’OPC ESO (2003-2004) (et membre d’un panel)
En cours :
CS European Interferometry Initiative (depuis 2003) (représentant francais)
Zins Gérard
OPTICON - Chef de projet JRA4
EII - Membre du board
19.1.4 SHERPA
J. Ferreira
Coleader du work package ”MHD Models” du RTN JETSET
G. Pelletier
Membre de commissions de la collaboration HESS (group leaders, speaker bureau).
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19.2 Organisation de colloques, workshops et autres conférences
19.2.1 FOST
Jean-Charles Augereau:
- Organisateur du 3eme atelier PNP/PNPS/PCMI: ”Formation des Systèmes Stellaires et Planétaires”, tenu à
CEA/Saclay, 26-27 mars 2002. (http://www-laog.obs.ujf-grenoble.fr/ augereau/ATELIER/ )
- Organisateur du 4eme atelier PNP/PNPS/PCMI: ”Physico-chimie des disques protoplanétaires et couplage
grain/gaz”, LAM, 17-18 janvier 2005. (http://www.lam.oamp.fr/claire/atpcmi/atelierPCMI.htm)
- membre du SOC de l’école du réseau européen PLANET: ”PLANET School and Network meeting: Spitzer’s
View on Star and Planet Formation”, Leiden, 14-18 Novembre 2005. (http://www.strw.leidenuniv.nl/cms/web/2005/2005
Jérôme Bouvier:
Membre du SOC des conférences suivantes:
- Atelier PNPS/Journées SF2A 2002, Paris, Juin 02
- Ecole Aussois, Oct. 2002: “Les Etoiles Massives: formation, structure, évolution”
- Forum Quadriennal PNPS 2002, Grenoble, Oct.02
- Ecole Aussois, Sept.05: ”Interactions dans les systemes composites: étoiles, disques et planètes”
- Multiple Stars across the HRD, Jul.05, Garching
- Protostars and Planets V, Hawaii, Nov.2005
- Membre du LOC des XXXIXth Rencontres de Moriond, ”Young Local Universe”, La Thuile, Aosta Valley,
Italy, March 21 - 28, 2004.
Almas Chalabaev:
-XXXIXth Rencontres de Moriond, ”Young Local Universe”, La Thuile, Aosta Valley, Italy, March 21 - 28,
2004. Membre du SOC, du LOC, et co-éditeur des actes
Catherine Dougados:
- Co-organistrice de la première école du FP6-RTN JETSET, Villard de Lans, France, Janvier 2006.
- Co-Organisatrice des journées du LAOG 2003
Gilles Duvert:
(2002-présent): membre LOC de l’école ERCA (European Research Course on Atmospheres)
Fabien Malbet:
- EuroWinter School, ”Observing with the VLTI” (mariotti.fr/obsvlti), Les Houches, 3-8 février 2002
- JENAM’2002, workshop ”The VLTI Challenges for the Future”, Porto, 5-7 septembre 2002
- Journée PNP ”A la recherche du photon planétaire”, Semaine de la SFSA, Paris 28 juin 2002
- Journée VLTI, Semaine de la SF2A 2004, Paris, le 17 juin 2004
François Ménard:
- Co-Organisateur de la session 78 des écoles d’été des Houches / NATO Advanced Study Institute: ”Accretion
discs, jets, and High energy phenomena in astrophysics”, 29 juillet- 23 aout 2002, Les Houches, France.
- Organisateur de l’atelier du Télescope Canada-France-Hawaii: ”PUEO NUI Science Case Workshop”, tenu à
Grenoble, 22-23 Mai 2003.
Jean-Louis Monin:
- membre du SOC de la conférence ”IAC/TNG workshop on Ultra Low Mass Formation and Evolution”, La
Palma, Espagne, 28 juin- 1 juillet 2005.
19.3 Responsabilités individuelles locales et nationales
19.3.1 Astromol
Ceccarelli Cecilia
Membre du Conseil Scientifique du LAOG (2003-2006)
Coordinator du Group WAGOS (Working Astrophysics Group of Star Formation), financé par le Projet National
PCMI (2002-2006)
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Chef de l’ Equipe ASTROMOL du LAOG (2003-2006)
Kahane Claudine
Membre du Jury de concours de l’Agrégation de Physique (2000 a 2003).
Directrice adjointe UFR de Physique UJF : de juillet 2000 a juillet 2002.
CEVU UJF : membre élu depuis janvier 1998.
Commission des Finances UJF : membre élu depuis janvier 1998 (dont Présidente de 1998 a 2001).
Directrice du Département Scientifique Universitaire UJF : depuis mai 2003.
Bertrand Lefloch
Membre du Conseil Scientifique du LAOG (2003-2006)
Membre de la commission specialistes de Physique UJF depuis (2003-2006)
Membre de la commission specialistes en section 34 de l’Universite de Provence Aix-Marseille (2003-2006)
Membre du Conseil Scientifique du programme PCMI (2005-2006)
Montmerle Thierry
Direction du LAOG (2003 2006)
Membre du Conseil Scientifique du Programme National ”Physique et Chimie du Milieu Interstellaire” (1996-
2004)
Membre du Conseil de la Société Francaise d’Astronomie et d’Astrophysique (1999-2003)
(1998-2002) Responsable du segment ”Etoiles et galaxies” du CEA Valiron Pierre
Membre élu au CS du département SdU et de l’INSU et participation á la CSA (2001-2005)
Président du comité thématique “ Astrophysique, Géophysique, Terre solide” pour les centres de calcul nationaux
IDRIS et CINES (2000-2004)
Membre du CS de l’ACI GRID (2002-2006)
Membre du CS de l’Action Spécifique Observatoire Virtuel (ASOV) de l’INSU (2005-2006)
Membre du CS de l’Action Spécifique Simulation Numérique en Astrophysique de l’INSU (-2006)
Responsable des moyens communs de calcul intensif de l’Observatoire des Sciences de l’Univers de Grenoble
(-2006)
19.3.2 FOST
Herve Beust
(2000-présent): Responsable de la coordination des stages d’étudiants au LAOG
(2003-présent): membre elu du conseil de Laboratoire du LAOG
Jerome Bouvier:
(1998-2002): Directeur du PN Physique Stellaire (PNPS)
(1997-2003): Membre du CNAP (nommé)
(2001-2003): Membre du Groupe ad’hoc Astrophysique du CNES
(2001-2002): Membre de la CSE de l’UFR de Physique, UJF (nommé, demission)
(2002): Membre du Conseil de l’OSU du CRAL
(1997-2003): Membre du Conseil de laboratoire du LAOG
(1998-2003): Membre du TAC Télescopes Nationaux PNPS
(2000-2002): Membre Groupe Prospective Spectroscopie Intégrale de Champ PNPS (chair)
(2003): Membre du Comité d’Evaluation de l’IAP
(2001-2004): Membre Groupe de Suivi Opération GI2T (chair)
(2002-2004): Membre du Groupe de Suivi NARVAL/TBL
(2005-présent): Membre CSD6 ANR ”Sciences de l’Univers et Géoenvironnement” (nommé)
(1999-présent): Membre CSA INSU
(2004-présent): Membre du Conseil de la SF2A
(2003-présent): Représentant du LAOG au CNFA
(2004-présent): Membre CSE Montpellier
(2004-présent): Membre CSE Lyon
Xavier Delfosse:
(2003-présent): membre du conseil de Laboratoire du LAOG
(2002-présent): président de la commission communication du LAOG
(2002-présent): membre de la cellule communication de l’OSUG
(2004-présent): membre du groupe scientifique de l’instrument OHP/SOPHIE
Catherine Dougados:
172

(2003-présent): Membre du CNAP, section astronomie. Membre du bureau, secrétaire
(2004): Membre de la CSE de l’Observatoire de Paris
(1999-2002): Membre du conseil de Laboratoire du LAOG
Gilles Duvert:
-Membre du conseil scientifique de l’action spécifique Observatoire Virtuel (AS OV)
-Responsable de l’informatique du LAOG
-Membre de la Commission Services Observation de l’OSUG
-Membre de la Commission Services Communs de l’OSUG
Anne-Marie Lagrange:
(2002-présent): Directeur scientifique adjoint ”Astronomie-Astrophysique de l’INSU.
Fabien Malbet:
(2003-présent): Membre du Conseil Scientifique du Programme National de Physique Stellaire, Webmestre du
site internet du PNPS
(2004-présent): Membre du groupe d’expert exoplanètes pour la CSA
(1999-2002): Animateur du Sujet Fléche ”exoplanètes” du Programme National de Planétologie
(1999-présent): Membre du Conseil de Laboratoire du LAOG
François Ménard:
(1995-2004): Responsable scientifique du polarimètre STERENN du Pic-du-Midi
(2001): membre de la CSE de l’UFR de Physique, UJF
(2003-présent): membre du conseil de Laboratoire du LAOG
(2002-2004): Membre du Groupe de Suivi NARVAL/TBL
(2004): Membre du comité d’évaluation du GEPI
(2004-présent): Membre (élu B1) de la section 17 du comité national du CNRS
(2005): Membre du comité de revue du projet ELP-OA (représentant PNPS)
(2004-2005): Membre du comité français d’allocation du temps de télescope du TCFH
(2005-présent): Membre du Conseil de l’OSU du CRAL
(2005): membre du comité d’évaluation du CRAL, représentant section 17
(2002-présent): Responsable de l’équipe FOST du LAOG
Jean-Louis Monin:
(jusqu’en 1002) : Responsable du DEA ’Astrophysique et milieux dilués de l’UJF
(2001-2002) : Directeur Scientifique MSU DS3 au ministère de la recherche
(2004- présent) : Directeur adjoint du LAOG
(2003- présent) : membre du CNU 34
(2003-présent) : membre du CS de l’UFR de Physique
(2002-présent): membre de la CSE à Besancon
(2003-présent): membre de la CSE à Strasbourg
19.3.3 GRIL
Beuzit Jean-Luc
Conseil National des Astronomes et Physiciens (CNAP): 2004-2005
P.I. du VLT-PF (instrument seconde generation ESO/VLT)
Chelli Alain
Membre du Conseil de Laboratoire du LAOG
Directeur du JMMC
Membre du Conseil Strategique HRA (cshra)
Membre du bureau de la HRA
Duvert Gilles
Membre CS JMMC
Membre CS AS Observatoire Virtuel
Membre Nomme Commission Services Observation OSUG
Membre élu Commission Services Communs OSUG
directeur technique JMMC
responsable logiciel traitement données AMBER
Feautrier Philippe
Trésorier Bureau du CAESUG
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jury de concours:
1 concours IR CNRS Meudon Bellevue en 2004
1 concours IR CNRS Grenoble en 2005
1 jury d’amnissibilité IR MEN Bap C en 2005
Kern Pierre
Membre du CS de l’ASHRA jusqu’en janvier 2005
Membre du bureau de Alpes Optique et Photonique jusqu’en 2004 (opticiens du sillon Alpin) (inclue l’organisation
de congrès)
Co-chef de projet AMBER
Jury de concours IE et IR des universités en qualité d’expert (1 à 2 fois par an)
Commission paritaire OSUG
Organisation de l’Ateliers de l’Optique en Astronomie (Atelier INSU) Grenoble du 5 au 7 mars 2001 (200 personnes
, actes)
Le Coarer Etienne
commissions de l’université : conseil scientifique
CAESUG : suppléant CA
jury de concours : expert et président trois fois l’an
Perrier Christian
terminé:
Direction du LAOG - UMR 5571 (jusqu’à fin 2002), a ce titre:
Direction-adjointe de l’Observatoire des sciences de l’univers de Grenoble (idem)
Membre es-qualité du CA de l’OSUG et de diverses commissions (idem)
et du Comité directeur d’AMBER (jusqu’en 2003)
en cours:
Responsabilité de l’équipe de recherche instrumentale du LAOG (depuis 2003)
Président du CS de lÕASHRA (depuis début 2004)
a ce titre: membre de ses conseils et membre de la CSA (depuis 2005)
Membre de: CSSO de l’OHP (depuis 2003)
CA de l’OSU Marseille-Provence (depuis 2004)
Haut Conseil Scientifique de l’Observatoire de Paris (depuis 2003)
Comité scientifique français de lÕESO (depuis 2003) et Comité francais de l’ESO (idem)
Malbet Fabien
Membre du groupe d’expert exoplanetes pour le CSA (2004-)
Membre du Conseil Scientifique du Programme National de Physique Stellaire (2003-)
Journée PNP ”A la recherche du photon planetaire”, Seemaine de la SFSA, Paris 28 juin 2002
Journée VLTI, Semaine de la SF2A, Paris, le 17 juin 2004
Animateur du Sujet Fleche ”exoplanetes” au sein du Programme National de Planetologie (1999-2002)
AMBER Project Scientist
Membre du Conseil de Laboratoire du LAOG (1999-)
Webmaster du site Internet du PNPS
Perraut Karine
Membre elue de la commission ”Services d’observation” de l’OSUG de 2000 a 2004
Membre elue de la commission de specialistes de physique de l’UJF depuis 2004
Zins Gérard
JMMC - Membre du CS/Chef de projet
19.3.4 SHERPA
G. Henri:
Responsable du DEA, puis de la spécialité du Master 2
Recherche ”Astrophysique et Milieux Dilués” depuis 2002
Membre élu du CA de l’UJF depuis octobre 2002.
Membre des CSE de Strasbourg en 2002-2003, des CSE de l’ENS
Lyon et de l’Observatoire de Lyon depuis 2004 Membre du bureau de l’UFR de physique, chargé des relations
avec les
enseignants, depuis 2003.
174

Membre du conseil scientifique du LPSC depuis 2003
Membre du CNU 34 e section depuis 2002
Représentant du CNU au conseil scientifique de l’INSU depuis 2002
Membre de la commission des post-docs CNRS de l’IN2P3 depuis 2004.
J. Ferreira
Membre nommé de la CSE de lyon
G. Pelletier
Direction de l’équipe SHERPA du LAOG.
Président du conseil scientifique du laboratoire de Paris VII APC.
Membre du conseil scientifique du Laboratoire Physique Théorique et Astroparticule et de Montpellier.
Membre de la Commission de Spécialistes de Physique de l’UJF.
Membre du Conseil Scientifique du GdR PCHE.
Membre (jusqu’en 2004) du conseil scientifique de l’ENS Lyon.
175

Chapter 20
Appendix 4: The Jean Marie Mariotti
Center
For technical reasons, the JMMC report is written in French in this document. A translation in English should
follow shortly.
Au cours des années 90, le Programme National de Haute Résolution Angulaire (PNHRA), et par la suite
l’Action Spécifique Haute Résolution Angulaire (ASHRA), appuyés par le Laboratoire d’Astrophysique de
Grenoble et l’Observatoire de la Cote d’Azur ont promu la création d’un Centre d’Expertise en Interférométrie
Optique. En septembre 2000, le Centre Jean-Marie Mariotti (JJMC) ou Centre Mariotti a été crée par l’INSU
(voir l’organigramme 20.1).
20.1 Mission
La mission du JMMC est d’unir les compétences et de coordonner les efforts français en vue de l’exploitation
optimale de l’interférométrie optique. Ses vocations sont de :
• Développer, produire, documenter et maintenir les logiciels nécessaires à l’exploitation ainsi qu’au suivi
des nouveaux équipements, en particulier le VLTI.
• Stimuler la formation académique.
• Participer à la réflexion prospective autour des nouveaux instruments.
20.2 Structure
Le JMMC est un réseau de 11 Laboratoires français, assimilable à un laboratoire sans murs, doté d’un centre
de réalisation logicielle localisé au LAOG, d’un conseil scientifique et d’un bureau exécutif. Les Laboratoires
partenaires du JMMC sont les suivants :
• Département d’Astrophysique (Université de Nice-Sophia Antipolis, UNSA)
• Département Fresnel (Observatoire de la Côte d’Azur, OCA)
• IAS (Institut d’Astrophysique Spatiale, Orsay)
• LAOG (Laboratoire d’Astrophysique de Grenoble)
• LAT (Observatoire de Midi-Pyrénées)
176

• LESIA (Observatoire de Paris-Meudon)
• LISE (Observatoire de Haute Provence)
• IRCOM (Université de Limoges)
• Observatoire de Bordeaux
• Observatoire de Lyon
• ONERA (Châtillon)
20.3 Statut
En 2001, le JMMC a été inscrit par la CSA dans la liste des centres nationaux et internationaux de traitement
et d’archivage reconnus parmi les services d’observation de l’INSU. Depuis 2003, il est devenu le GdR # 2596
du CNRS, ce qui lui assure un financement récurrent sur 4 ans.
20.4 Budget
Le budget annuel moyen du JMMC est de 50KE en provenance du CNRS, auxquels doivent s’ajouter 70KE en
provenance de contrats européens. Il sert essentiellement à financer des missions et des CDD.
20.5 Direction et personnel
Depuis sa création, le centre Mariotti est piloté par son directeur Alain Chelli, et depuis 2003 par son directeur
technique Gilles Duvert pour faire face a la complexité croissante des taches de réalisation logicielle. Les personnels
scientifiques, de l’ordre de 25 chercheurs (approximativement 4 hommes.an équivalent plein temps),
évoluent dans son réseau de laboratoires. Les personnels techniques, 3 ingénieurs permanents et 1 CDD (tous
ITA CNRS), sont pour l’ensemble regroupés dans le centre de réalisation logicielle. Trois astronomes effectuent
actuellement leur tache de service au sein du JMMC, ce sont : Merieme Chadid (OCA), Gaspard Duchêne
(LAOG) et Pierre Kervella (LESIA).
20.6 Le centre de réalisation logicielle
Le centre de realisation logicielle localise au LAOG est forme par 3 ingénieurs permanents : Gerard Zins (Project
Manager), Laurence Gluck et Sylvain Lafrasse, et d’un CDD : Guillaume Mella.
Les projets du centre sont essentiellement des projets de réalisation d’” instruments logiciels ” mis en oeuvre,
coordonnés, réalisés, distribués et maintenus par les personnels en son sein. Les réalisations s’effectuent
dans un strict cadre projet sous la direction du chef de projet. Les produits logiciels du centre sont mis à la
disposition de l’ensemble des laboratoires de recherche en astrophysique français ainsi que de la communauté
des astronomes européens, soit par téléchargement, soit par la mise en place de services web. Le centre fournit
aussi une assistance utilisateurs, des didacticiels et des serveurs de documentation. Il a mis en place, maintient
et développe tous les services informatiques distribués reliés à la gestion et à la réalisation des projets du JMMC
et du projet européen OPTICON-JRA4 (voir http://mariotti.ujf-grenoble.fr et http://eii-jra4.ujf-grenoble.fr).
177

20.7 Production informatique
¡¢£¤¥¢¦¢¡§¨©¤¡¢� ��£¡©¥¢�£�¨��� �¢�£¡¥¨������������ ����������������������������������������������������������������������������������������������������������������������������������������������������������������� ������������������������������������������ ��������������������������������������� ��������������������������������������� ������������������������������ ������������������������� ����������������������������������������������������� ����������������������������������������������������������������������������������������������
Figure 20.1: Organigramme du JMMC
• ASPRO : logiciel généraliste de préparation aux observations interférométriques.
• ASPRO-VLTI : spécialisé dans la préparation des observations pour les instruments AMBER et MIDI du
VLTI, mis à jour chaque semestre en fonction des appels d’offre et des configurations proposées par l’ESO
sur ces instruments. Voir http://mariotti.ujf-grenoble.fr/ aspro.
• SearchCalib : logiciel ” Observatoire Virtuel ” de recherche d’étoiles de calibration pour les observations
interférométriques optiques.
• Logiciel FLUOR de réduction de données pour l’expérience FLUOR et les observations VLTI avec l’instrument
VINCI (maintenance arrêtée).
• Logiciel MIDI de réduction de données de l’instrument MIDI du VLTI.
• Bibliothèque de modules pour la réalisation d’un logiciel d’interprétation de données interférométriques
optiques (dans le cadre du projet européen OPTICON-JRA4)
• Logiciel XMLGui, Client-Serveur d’interface graphique pour des applications web.
20.8 Organisation de services informatiques distribués
• Serveur d’applications ASPRO et SearchCalib,
• Serveur de téléchargement d’applications.
• Serveur CVS et sauvegarde.
• Serveur de documentation.
• Serveurs WEB JMMC et JRA4.
• Serveur de liste de diffusion.
• Plateforme de travail collaboratif pour les équipes des Laboratoires partenaires du JMMC et les équipes
européennes du projet OPTICON-JRA4.
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20.9 Groupes de Recherche et Développement
Le VLTI est pour l’instant un interféromètre unique dans le sens ou il est conçu comme un instrument de
service géré par l’ESO. N’importe quel astronome peut faire une demande de temps avec le VLTI, observer
comme astronome visiteur et traiter ses données avec les logiciels développés par les consortia ayant construit
les instruments. Cependant, cela ne suffit pas pour faire du VLTI un réel instrument de service. Pour ce faire,
il faut développer les logiciels pour :
1. préparer les observations, c’est à dire examiner leur faisabilité,
2. calibrer les observations, c’est à dire sélectionner des calibrateurs,
3. Interpréter, les observables interférométriques en terme de modèles simples,
4. reconstruire si cela est possible, l ’image de l’objet.
Pour répondre à ces besoins, le JMMC a crée 4 groupes de recherche et développement. L’objectif de chaque
groupe est de fournir des algorithmes, éventuellement des logiciels prototypes, qui seront codés ou recodés par
les ingénieurs du centre de réalisation, appuyés au cas par cas par des ingénieurs des laboratoires partenaires.
• ASPRO (Responsable Gille Duvert, collaborations : LESIA, OCA): Ce logiciel simule les observations
avec le VLTI (ainsi que d’autres interféromètres). Il permet à l’issue de l’observation simulée de calculer
le rapport signal sur bruit sur les paramètres astrophysiques (diamètres, séparation, etc...) d’objets ou
de collections d’objets simples. La première version d’ASPRO, téléchargeable des pages web du JMMC,
a été délivrée en 2002. La seconde version, module de recherche de calibrateurs inclus et pourvue d’une
interface web, a été delivree en 2004. Chaque semestre, ASPRO-LIGHT, une version d’ASPRO adaptée
aux instruments et aux configurations du VLTI proposées par l’ESO, est mis à la disposition des utilisateurs.
• SearchCalib (Responsable Daniel Bonneau : OCA, collaborations : CDS. LAOG, LESIA, LUAN) : Les
observations interférométriques ont besoin d’être calibrées des effets de l’atmosphère et de l’instrument.
Le logiciel Searchcalib intégré dans ASPRO permet, en utilisant les avantages de l’observatoire virtuel,
de trouver les calibrateurs (source ponctuelle ou de diamètre connu) les mieux adaptés à une observation
donnée dans les domaines visible et infrarouge. Sa structure a été conçue avec l’objectif de créer un catalogue
de calibrateurs dynamique par la consultation en temps réel des catalogues de la base de données
VisieR au CDS. La première version de SearchCalib pour objets brillant (K≤5) a été délivrée en 2004, le
seconde version pour objets faibles (K≥5) est prévue pour 2006.
• Model Fitting (Responsable Isabelle Tallon-Bosc : CRAL, collaborations : LAOG, LUAN, OCA) :
L’objectif de ce groupe est développer un logiciel permettant d’interpréter les observables interférométriques
(visibilité, phase différentielle et clôture de phase) en termes de modèles géométriques simples combinables
(disque uniforme, source multiple, enveloppe, etc...). Depuis 2004, l’activité de ce groupe est devenue le
Work Package 2.3 ” Model Fitting ” du projet européen OPTICON-JRA4 (voir les projets européens).
Une première version de ce logiciel sera délivrée en 2006.
• Image Reconstruction (Responsable Eric Thiebaut : CRAL, collaborateur : ONERA) : L’objectif de ce
groupe est de fournir un logiciel de reconstruction d’images à partir de données interférométriques, adapté
au petit nombre de télescopes du VLTI. Deux logiciels prototypes ont été développés et sont en cours de
test et de comparaison avec d’autres logiciels. Depuis 2004, l’activité de ce groupe fait partie du Work
Package 2.5 ” Image Reconstruction ” du projet européen JRA4 (voir les projets européens). Une première
version de ce logiciel sera délivrée en 2007.
Pour tous ces logiciels, le JMMC a mis en place une assistance utilisateurs au niveau européen (Gaspard
Duchene, Pierre Kervella/LESIA).
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20.10 Formation des utilisateurs
La formation des utilisateurs des moyens interférométriques est une de nos missions. En février 2002 nous avons
organisé une école européenne aux Houches ” Observing with the Very Large Telescope Interferometer ”, centrée
sur la préparation des observations avec le VLTI (responsable Fabien Malbet). Nous prévoyons d’organiser 2
écoles en 2006 :
• Une école française à Porquerolles pour les ITA (la demande est forte) sur la haute résolution angulaire
en astrophysique (responsable Denis Mourard, OCA).
• Une école européenne aux Houches sur la préparation des observations et les premiers résultats astrophysiques
avec le VLTI (responsable Guy Perrin, LESIA). Cette école pourrait fusionner avec la première
école du projet Marie Curie (4 écoles interférométriques européennes de 2006 à 2009, voir Chapitre 5).
20.11 Conduite de projets européens
En 2002, des discussions ont débuté entre les 3 centres interférométriques européens, le JMMC pour la France,
FRINGE pour l’Allemagne et NEVEC pour la Hollande afin de promouvoir l’interférométrie et de contribuer
à générer une vision européenne. Les discussions se sont vite élargies à douze pays (Allemagne, Autriche, Belgique,
France, Hollande, Hongrie, Israel, Italie, Pologne, Portugal, Royaume Unis, Republique Tcheque) ainsi
qu’à l’ESA et l’ESO, et ont abouti à la création de l’Euro-Interférométrie Initiative (EII).
20.12 L’Euro-Interferometry Initiative
L’EII consiste en l’ensemble des projets interférométriques développés dans un cadre européen. L’EII est dotée
d’un bureau formé par l’union des bureaux des projets la composant (les représentants français au bureau de l’EII
sont : Alain Chelli, Gilles Duvert, Denis Mourard/OCA, Romain Petrov/LUAN et Guy Perrin/LESIA) et d’un
conseil scientifique présidé par Thomas Henning (Heidelberg) et formé par les représentants de chacun des pays
(Christian Perrier pour la France). Les missions de ce conseil scientifique européen sont de maintenir et renforcer
l’interférométrie européenne, intégrer de nouveau pays, favoriser la formation et l’échange de visiteurs et enfin
générer une vision long terme. Ses règles de fonctionnement sont régies par un Memorandum of Understanding
(MoU) approuvé par les représentants de chaque pays. En 2004 deux projets ont été proposés et acceptés
dans le cadre de l’I3 européen OPTICON : le Joint Research Activity # 4 (JRA4) ” Integrating Interferometry
into Mainstream Astronomy ” (centré sur le VLTI) coordonné par Alain Chelli, et le Network5 (centré sur
l’échange de visiteurs et la prospective) coordonné par Andreas Quirrenbach (Leiden). Pour compléter ce cadre,
un projet Marie-Curie de 4 écoles européennes à forte composante interférométrique, coordonné par Paolo Garcia
(Porto), vient récemment d’être accepté par l’Europe (voir 20.2 la structure de l’EII et ses liens avec le FP6).
Le JRA4 ” Integrating Interferometry into Mainstream Astronomy ” (voir http://eii-jra4.ujf-grenoble.fr): Le
JMMC a une part déterminante dans le JRA4. Ce projet, centré sur le VLTI, est l’un des 6 JRA d’OPTICON.
Il implique tous les pays participants de l’EII, l’ESA et l’ESO et regroupe plus d’une vingtaine de laboratoires.
Il est doté d’un budget de 1 ME étalé sur 5 ans, dont 260KE pour la partie française, également repartis sur 2
Work Packages. La structure du JRA4 est la suivante (voir la 20.3):
• WP1.1 ” Concept to feasibility studies ” : Le WP1.1 est co-dirigé par Denis Mourard (OCA). Il a pour
objectif de préparer la seconde génération d’instruments du VLTI et est divisé en 2 phases : une phase
d’études de concept suivie d’une phase d’études de faisabilité. Les études de concept ont pris fin en avril
2005 et les résultats ont été présentés au workshop commun l’ESO et de l’EII ” The Power of Optical/IR
Interferometry : Recent Scientific Results and Second Generation VLTI Instrumentation ” d’avril 2005
à Garching. Elles regroupent 6 instruments : 2 recombinateurs visibles et 4 recombinateurs infrarouges.
Dans sa résolution d’avril 2005, le conseil scientifique de l’EII a recommandé à l’ESO de démarrer 2 études
de phase A pour un imageur 4-6 télescopes et a classé en priorité les concepts APRES-MIDI (extension
180

¡ ¢£¤¥¦§¨¤¥©¢£�§¨�¤§��¤�§¥¢£�¤�¨¤��¥��¢�� ������� ���������������������������������������������������������� ������������������������������������� ���������������������������������� �������������� ����������������� ���Figure
20.2: Structure de l’Euro-Interferometry Initiative
de l’instrument 10µm MIDI de 2 à 4 voies, responsable Bruno Lopez/OCA) et l’instrument VITRUV
(imageur 4-8 voies IR proche en optique intégrée, responsable Fabien Malbet). Les études de faisabilité
démarreront dès que le conseil de l’ESO aura sélectionné les instruments VLTI de seconde génération.
• WP1.2 ” Co-phasing and Fringe Tracking ”: Le WP1.2 est dirigé par Mario Gai (Torino). Il a pour
objectif d’optimiser les performances des instruments de co-phasage. Pour ce faire, un groupe de travail
européen a été formé et les taches ont été distribuées. Ce travail est en cours.
• WP2 ” Off-line data reuction software ”: Le JMMC est maître d’oeuvre du WP2 (responsable : Gilles
Duvert, Project Manager : Gerard Zins), la partie logicielle du JRA4. Ce projet fournira la communauté
des utilisateurs européens du VLTI et du LBT (Large Binocular Telescope) un logiciel d’aide à
l’interprétation des observations interférométriques. Il a été divisé en 5 parties :
– WP2.1 ” Management and user support ” : Responsable Gilles Duvert, Project Manager Gerard
Zins. Création du site web du JRA4 avec tous les services de communication entre les groupes,
documentation, rapports, etc... Un support utilisateur (Gaspard Duchêne, Pierre Kervella/LESIA a
été mis en place.
– WP2.2 ” Common software ”: Responsable Gilles Duvert, Project Manager Gerard Zins. Développement
d’une librairie de base pour les processus de communication, manipulation d’erreurs, règles de programmation.
L’écriture de la librairie est pratiquement terminée.
– WP2.3 ” Model Fitting ” : Responsable Isabelle Tallon-Bosc/CRAL, collaborations : LAOG, LUAN,
OCA. Logiciel de modélisation des observables interférométriques (voir la section la section ” Model
Fitting ” des Groupes de Recherche et Développement). Une première version de ce logiciel sera
délivrée en 2006.
– WP2.4 ” Astrométrie ” : Responsables Didier Queloz (Observatoire de Geneve), Andreas Quirrenbach
(Leiden). Calcul de mouvements propres et de paramètres orbitaux de systèmes multiples,
développement d’un traitement de données interactif pour l’instrument PRIMA. La première version
de ce logiciel sera délivrée en 2007.
– WP2.5 ” Image Reconstruction ” : L’objectif est de fournir à la communauté deux logiciels de
reconstruction d’images pour le VLTI, l’un original développé par le CRAL et l’ONERA et l’autre
adapté des algorithmes radio par l’université de Grenade, ainsi qu’un logiciel dédié aux données du
LBT développé par le MPIA et le MPIfR. Une première version de ces logiciels sera délivrée en 2007.
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20.13 Darwin
¡¢£¤¥¦§¨©��¤¦ ���������������������� ��������������������������������������������������������� �������������������������� ������������������ �������������������������������������������������� ����������������������������������������������������������� �������������������������������������� ��������������������������������� ���������������������� �������������������
����������
Figure 20.3: Structure du JRA4
Darwin est une mission de l’ESA, prévue pour après 2015, dont l’objectif ambitieux est de détecter des traces
de vie extraterrestre sur des exo-planètes de type tellurique. C’est un interféromètre spatial à 3 telescopes
fonctionnant à 10µm en mode frange ” nulling ”. En 2004, le JMMC en collaboration avec Alcatel Space a
remporté l’appel d’offre de l’ESA ” Reconstruction of Exo-Solar Properties ”, doté d’un budget de 190KE, dont
80KE pour le JMMC. Il s’agit d’une étude sur 18 mois visant à simuler les cibles (Origin) et à développer les
algorithmes de détection et de caractérisation des planètes à partir des mesures de DARWIN. Le JMMC est
responsable de la partie scientifique : responsable Eric Thiebaut/CRAL, collaborateurs : IAS, LUAN, ONERA.
20.14 Relations avec l’ESO et le MSC
Dès sa création, le centre Mariotti a cherché à établir un accord de collaboration avec l’ESO pour la fourniture
de services informatiques. Les activités du JMMC ont été présentées aux responsables du VLTI, à la Directrice
Générale lors de sa visite au LAOG, ainsi qu’au comité des utilisateurs de l’ESO. A chaque fois, le JMMC a
reçu un accueil très favorable, mais rien ne s’est concrétisé jusqu’à présent. Il est à noter toutefois que le moteur
de calcul du logiciel de l’ESO de préparation des observations avec le VLTI est basé sur celui d’ASPRO (lien
sur le JMMC de la page web du VLTI). La situation pourrait évoluer avec les nouveaux responsables du VLTI
qui ont officiellement exprimé le désir de visiter les 3 centres interférométriques européens (JMMC, FRINGE et
NEVEC) pour étudier les possibles collaborations. La visite du responsable du VLTI au JMMC aura lieu le 20
octobre prochain. A suivre ...
Le Michelson Science Center (MSC, CalTech) est en charge de l’interféromètre Keck et à ce titre, il a les
mêmes préoccupations logicielles et de formation que les centres interférométriques européens. Il existe aussi
une forte tradition de collaboration entre les interférométristes français et leurs collègues américains du MSC.
C’est donc naturellement, à la suite de visites réciproques de leurs responsables en 2004 et 2005, que le JMMC
et le MSC ont manifesté leur désir de collaborer dans des actions logicielles et de formation, et de faciliter
l’échange de visiteurs. Pour initier la collaboration, il a été décidé d’appuyer 1 à 2 visiteurs par an dans chaque
sens.
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20.15 Prospective
Le centre Mariotti continuera à assister les utilisateurs, ainsi qu’à maintenir et à mettre à jour les produits
logiciels qu’il met à la disposition de la communauté. A titre d’exemple, il sera nécessaire d’adapter le logiciel
de préparation des observations aux nouvelles configurations du VLTI ainsi qu’aux instruments de seconde
génération et de fournir un logiciel de recherche de calibrateurs pour les objets faibles. Le logiciel européen est
à l’heure actuelle un logiciel minimum, il faudra le compléter par d’autres fonctions comme la possibilité de
permettre à l’utilisateur d’utiliser ses propres modèles astrophysiques pour interpréter ses mesures.
Le JMMC participera activement au développement du traitement des données des d’instruments de seconde
génération du VLTI, ainsi qu’aux simulations de leur capacité d’imagerie.
Nous préparons 2 écoles interférométriques pour 2006 (une école pour les ITA et une école européenne) et
nous serons fortement impliqués dans l’organisation des 4 écoles européennes dans le cadre du projet Marie Curie.
Avec l’ASHRA et nos collègues européens, nous commençons à préparer le prochain programme européen
(FP7). Suite à des discussions préliminaires au niveau français, nous pourrions proposer à nos partenaires
européens un projet interférométrique ambitieux alliant le sol (VLTI, Antartique, post-VLTI, ...) et l’espace
(Darwin). Le projet Darwin est une de nos priorité, nous comptons répondre aux appels d’offre de l’ESA concernant
les développements logiciels associés.
Au-delà des aspects scientifiques, notre préoccupation actuelle est la pérennisation du centre Mariotti, en
particulier de son centre de réalisation logicielle. Celui-ci devrait déménager en 2007-2008 dans un nouveau
bâtiment adjacent au LAOG (CERMO, action appuyée par l’UJF). Le GdR centre Mariotti prendra fin en
2006, nous réfléchissons à la structure la mieux adaptée dans laquelle le JMMC pourra être renouvelé (GdR ou
autre).
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