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Each tile is centered at a well-defined position. The coordinates of a stack center position are identical for all filters. W1, W2, W3 and W4 are therefore composed of a complete set of u ∗ , g, r, i, y and z adjacent square tiles of 1 deg 2 each. The integer part of the center position of each tile is used to name the final stacks and other data products. This naming convention was agreed by CADC, Terapix and the CFHTLS Steering Group and is valid for all CFHTLS releases. In addition to the official astronomical CFHTLS naming convention, Terapix defined in 2002 a shorter naming convention based on a Cartesian grid coordinate system, where the increment unit is a MegaCamsize field and the center positions of the grid points are the center positions of the tiles 21 . The reference center of each Wide field of view is defined as the reference W[1, 2, 3, 4](0,0) and the Cartesian field names increase toward the East and North. The tiling and field naming conventions are drawn on Fig. 20 and the complete list of the T0007 Wide stacks is given in Tables 31. The total exposure time per filter is approximately the same for each tile (see Table 31 and the synoptic table). For some tiles, the exposure time is longer than the nominal value, because exposures that were considered out of spec by QSO and hence immediately reobserved have been later on salvaged at the post processing time. It produces very sharp exposure time distributions for all filters (see Fig. 23). Some observations have been adjusted to take into account unexpected events (like absorption by clouds/cirrus or technical problems). There are a few fields that have deeper u ∗ -band and z-band exposures which explains the small tails shown in the inset of Fig. 23. These longer exposures were taken before it was decided to cut the u ∗ and z exposure times by a factor of two at the survey mid-term review (2005). In addition to the original CFHTLS exposures, the VIPERS consortium took complementary exposures to fill in the holes in W1 which were caused by malfunctioning CCDs later in 2003. These images (distributed in 6 pointings and three filters u,g and y) have been added to T0007. As a result, these pointing are deeper than the rest of the survey. A detailed description of the added VIPERS-DDT images can be found in Table 5. Their position on the W1 patch are shown in Figure 22. Wide position Filter Exposure time (per image) Number of exposures [s] W1+2+2 u.MP9301 600 6 W1+4+2 g.MP9401 290 7 W1+3+1 g.MP9401 290 5 W1+3+1 g.MP9401 290 5 W1+4+1 g.MP9401 290 5 W1+2+1 i.MP9702 300.096 7 W1+3+2 i.MP9702 300.092 5 Table 5: Description of the 40 additional VIPERS-DDT images. All r-band stacks combine data taken during two epochs separated by at least two years and totalling 21 http://terapix.iap.fr/cplt/oldSite/Descart/summarycfhtlswide.html 32
Figure 22: Position of the additional VIPERS-DDT exposures used to fill in the holes in the survey. Top left: u ∗ -band, top-right: g-band, lower left: y-band. lower-right: filter mask coverage of the W1 Wide patch (See Section 6 for the meaning of the flags). Seven fields still remain with half-CCD holes in one or more filters due to the malfunctioning of some CCDs late 2003. These anomalies are listed in Tables 15 and 16. 2×500 s each. In all filters except u ∗ , observations were carried out only when the seeing (FHWM) was below 0.95". For the u ∗ -band, this rule was relaxed to 1.3". The complete list of CFHTLS input images that were combined into the Wide stacks is given in the Appendix A.2, in Table 32. The global properties of the CFHTLS Wide survey are summarized in Table 4 and in more detail in Table 6. Overall, they meet the survey specifications but the homogeneity of the survey over a Wide patch scale must be assessed carefully. The Wide field-to-field and MegaCam tile-to-tile scatters will be explored in detail in the following sections. The depth, the seeing, the photometric errors analysis are presented in the next parts of the document. Finally, the complete set of configuration files used for the T0007 release is presented in the Appendix. They are intended for users who would prefer to re-process the pre-processed or the stacked images with parameters tuned for their own scientific projects. The configuration files are available on request from Terapix. 33
Page 1: T0007 : The Final CFHTLS Release Pa
Page 4 and 5: patches are provided. Sources from
Page 6 and 7: Contents 1 CFHTLS-T0007 Executive S
Page 8 and 9: B.1 Rescaling factors applied to de
Page 10 and 11: 33 Galaxy counts for the four Wide
Page 12 and 13: 30 Description of parameters listed
Page 14 and 15: B A B A B A B A B A B A B A B A B A
Page 16 and 17: constraints. Two series of Deep sta
Page 18 and 19: evealed minor problems (such as unu
Page 20 and 21: een preferable because of the highe
Page 22 and 23: Figure 5: Outputs of the SCAMP cali
Page 24 and 25: Figure 7: CFHTLS T0007 absolute pho
Page 26 and 27: Figure 8: Seeing FWHM distribution
Page 28 and 29: Figure 10: Aperture correction (def
Page 30 and 31: Filter u g r i z - ApCorr - ApCorr
Page 32 and 33: Figure 14: Photometric calibration
Page 34 and 35: Figure 17: Photometric calibration
Page 36 and 37: Figure 18: Matching between one L99
Page 38 and 39: • four (u, g, r , i/y, z) Wide pa
Page 40 and 41: W1 W2 N N E E W3 W4 N N E E Figure
Page 42 and 43: CFHTLS Reference center Total Total
Page 46 and 47: Field Parameter u ∗ g r i y z W1
Page 48 and 49: Figure 23: Distribution of exposure
Page 50 and 51: Figure 25: Distribution of the medi
Page 52 and 53: All CFHTLS Wide images: (mean CCD s
Page 54 and 55: 50% completeness are given for poin
Page 56 and 57: 80% completeness limit (stars) 26.0
Page 58 and 59: 10 5 W1 W2 W3 10 5 W1 W2 W3 N gal 0
Page 60 and 61: Wide Field Magnitude range u ∗ g
Page 62 and 63: Wide Field Magnitude range u ∗ g
Page 64 and 65: paths. From the joint effort betwee
Page 66 and 67: Wide field External magnitude offse
Page 68 and 69: Wide field External rms errors with
Page 70 and 71: Figure 38: Comparison of one CFHTLS
Page 72 and 73: 4.5.2 Absolute astrometric accuracy
Page 74 and 75: 4.6 Outliers, stacks with exception
Page 76 and 77: Figure 40: Mean RA-DEC offsets betw
Page 78 and 79: Figure 42: Mean RA-DEC offsets betw
Page 80 and 81: W Cartesian CFHTLS Special filter V
Page 82 and 83: accurately reflect the integration
Page 84 and 85: Field Parameter u ∗ g r i y z D1-
Page 86 and 87: Field Parameter u ∗ g r i y z D1-
Page 88 and 89: 76 Figure 43: Comparison of the (u
Page 90 and 91: Figure 44: Estimation of the intern
Page 92 and 93: 5.4 Depth and completeness limits T
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D2 u−band (25% best−seeing imag
Page 96 and 97:
log Ngal 0.5 mag −1 deg −2 5 4
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- there is one chi2 image per Wide
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File name Content Data Size Number
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File name Content Data Size Number
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6.3 Content of CFHTLS source catalo
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stacks made with the y-(i.MP9702) f
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Id Parameter Description Units Comm
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6.4 The QualityFITS input and outpu
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Figure 48: QFITS-out page of the W4
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102
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Figure 51: Upper panel: CFHTLS all-
Page 118 and 119:
A CFHTLS T0007 Wide supplementary i
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Table 31 - Continued from previous
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A.2 List of images in each Wide sta
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Page 126 and 127:
Page 128 and 129:
Page 130 and 131:
Page 132 and 133:
Page 134 and 135:
Page 136 and 137:
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DISTORT_GROUPS 1,1 # Polynom group
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#--------------------------- Photom
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#--------------------------- Photom
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#--------------------------- Photom
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#--------------------------- Backgr
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#--------------------------- Backgr
Page 150 and 151:
#------------------------- Star/Gal
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#--------------------------- Star/G
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B.2 CFHTLS T0007 Deep configuration
Page 156 and 157:
SCAMP astrometric run using interna
Page 158 and 159:
SCAMP photometric run (D1,D2,D3,D4)
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B.2.2 SWarp stack configuration fil
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B.2.3 SWarp chi2-image configuratio
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B.2.4 SExtractor .ldac catalogue co
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B.2.5 SExtractor DUAL MODE .cat cat
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Acronyms & Abbreviations ASCII CADC
Page 170 and 171:
References Astier, P., et al. 2006,
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