Observational Constraints on The Evolution of Dust in ...

More documents

Recommendations

Info

30 New Young Stellar Population in Serpens 2.3.2 TNG Data The observations with DOLORES used the long-slit mode. Slit rotation was calculated in order to enable more than one object in the slit whenever two targets were closer than the length of the slit (8 ′ ). The wavelength range of ∼1600 Å was centered at 7000 Å, again including the Hα and Li i (6707 Å) lines, with resolving power R ∼ 2500. Exposure times ranged from 12 to 1000 seconds. Flat fields, bias, and argon comparison arc lamp spectra were obtained at the beginning of each night. After bias subtraction and flat fielding, the spectra were extracted and wavelength calibrated with a combination of the Ar arc lamp data and airglow lines 2 , including the OH Meinel bands, using the “doslit” task of the specred package in IRAF. Sky subtraction was done during the extraction based on the off-source regions along the slit. In total, we obtained DOLORES spectra of 18 sources, 15 of which were also observed with WYFFOS. 2.3.3 CAFOS Data CAFOS was used with mask observations in 2008 June. Three masks were taken using the grism R-100. Flat fields, bias, and HgCd/He/Rb comparison arc lamp spectra were obtained at the beginning of each night. The wavelength coverage (3500 Å, centered on 7750 Å) for each source varies slightly depending on their position on the CCD, with resolving power R ∼ 3523. The exposure time of 2400 seconds for each mask was divided into two for cosmic-ray rejection. After bias subtraction and flat fielding, the fields were divided so that each source would be in an image by itself and then further reduced as standard slit observations: the spectra were extracted and wavelength calibrated using the “doslit” task of the specred package in IRAF, performing sky subtraction during the extraction based on the off-source regions along each slit. The low resolution of these instruments, combined with low signal-to-noise (S/N) for most faint objects, did not allow us to detect or put meaningful upper limits on the Li i (6707 Å) line. 2.4 Spectral Classification Two methods were used in the spectral classification of the sources and are explained below. 2.4.1 Method I The objects were classified following the spectral classification scheme of Hernández et al. (2004) optimized to classify early type stars (up to early G). For stars with spectral type later than G, the scheme was extended by incorporating spectral indices for the 2 http://astro.u-strasbg.fr/∼koppen/divers/AirGlow.html
Evolution of Dust in Protoplanetary Disks 31 Figure 2.3 – Features used in the spectral type classification scheme of Hernández et al. (2004) are shown on the spectrum of source # 113. (A color version of this figure is available in the online journal) ranges G0–K5 and K5–M6 (Sicilia-Aguilar et al. 2005, Briceño et al. 2005 3 ). More information about this classification scheme can be found in the references above. In short, it is based on strong spectral features that are sensitive to T eff but insensitive to reddening in a specific luminosity class (dwarf in this case), since it uses local continua for the determination of the feature’s equivalent widths (EW). It is also designed to avoid problems caused by non-photospheric contributions (e.g. emission lines). The wavelength range of the WYFFOS spectra covers 12 of these features for all spectral types, while DOLORES covers 6 and the range of CAFOS covers 15 features. On average, 6 features for WYFFOS, 5 features for DOLORES, and 7 features for CAFOS were used for each classification, as exemplified in Figure 2.3. The spectral types calculated from each feature result in a weighted mean spectral type. The errors in the estimated spectral types have two contributions: the error in the measurement of each feature and the error of its fit to the standard (see Hernández et al. 2004 for more details). A few objects were observed in both runs (as can be seen in Table 2.1). For these objects, both spectra were ran separately through the spectral classification code. Their spectral classifications were found to be consistent with each other, typically within one subclass. 2.4.2 Method II Due to telluric absorption features not corrected for in the spectra presented here, care needs to be taken when using automatic fitting of features very close to these telluric bands. To make sure that the spectral types derived in Method I are correct, an additional spectral typing procedure was applied to the data. The library of standard spectra from Mora et al. (2001), covering the wavelength range of 5800–7000Å, was used in this method. In this region, different lines and bands 3 Information about the code can be found at http://www.astro.lsa.umich.edu/∼hernandj/SPTclass/sptclass.html
Page 1: Observational <str
Page 4 and 5: Promotiecommissie Promotor: Co-Prom
Page 6 and 7: Cover Artwork: Roderik Overzier
Page 8 and 9: viii Chapter 3. YSOs in the Lupus M
Page 10 and 11: x Publications 217 Acknowledgments
Page 12 and 13: 2 Introduction planets may eventual
Page 14 and 15: 4 Introduction Figure 1.1 - Illustr
Page 16 and 17: 6 Introduction 1.3.1.1 Disk Observa
Page 18 and 19: 8 Introduction 1.3.1.3 Processes Af
Page 20 and 21: 10 Introduction of them (e.g., β P
Page 22 and 23: 12 Introduction responsible for dis
Page 24 and 25: 14 Introduction Figure 1.4 - Eviden
Page 26 and 27: 16 Introduction stars (due to spect
Page 28 and 29: 18 Introduction the potential to ch
Page 30 and 31: 20 Introduction Gorti, U., Dullemon
Page 33 and 34: 2 Optical Characterization of a New
Page 35 and 36: Evolution of Dust in Protoplanetary
Page 39: Evolution of Dust in Protoplanetary
Page 59: Evolution of Dust in Protoplanetary
Page 62 and 63: 52 YSOs in the Lupus Molecular Clou
Page 87 and 88: 4 A Spitzer Survey of Protoplanetar
Page 91 and 92:
Evolution of Dust in Protoplanetary
Page 93 and 94:
Page 95 and 96:
Page 97 and 98:
Page 99 and 100:
Page 101 and 102:
Page 103 and 104:
Page 105 and 106:
Page 107 and 108:
Page 109 and 110:
Page 111 and 112:
Page 113 and 114:
Page 115 and 116:
Page 117 and 118:
Page 119 and 120:
Page 121 and 122:
A. Background Sources 111 Table 4.3
Page 123 and 124:
A. Background Sources 113 Figure A.
Page 125:
A. Background Sources 115 Figure A.
Page 128 and 129:
118 Discovery of a Dusty Planetary
Page 130 and 131:
Page 132 and 133:
Page 134 and 135:
Page 136 and 137:
Page 138 and 139:
128 From Protoplanetary Disks to Pl
Page 140 and 141:
Page 142 and 143:
Page 144 and 145:
Page 146 and 147:
Page 148 and 149:
Page 150 and 151:
Page 152 and 153:
Page 154 and 155:
Page 156 and 157:
Page 158 and 159:
Page 160 and 161:
Page 162 and 163:
Page 164 and 165:
Page 166 and 167:
Page 168 and 169:
Page 170 and 171:
Page 172 and 173:
Page 174 and 175:
Page 176 and 177:
166 Spectral Energy Distributions o
Page 178 and 179:
Page 180 and 181:
Page 182 and 183:
Page 184 and 185:
Page 186 and 187:
Page 188 and 189:
Page 190 and 191:
Page 192 and 193:
Page 194 and 195:
Page 196 and 197:
Page 198 and 199:
Page 201 and 202:
Nederlandse Samenvatting Inleiding
Page 203 and 204:
193 Figuur 1 - Het ontstaan van een
Page 205 and 206:
195 kunnen worden om de verschillen
Page 207 and 208:
197 Figuur 3 - Het planeetvormingsp
Page 209 and 210:
199 parameter is. Na 6 tot 8 miljoe
Page 211 and 212:
201 van de X-shooter in het ultravi
Page 213 and 214:
Resumo em Português Restrições O
Page 215 and 216:
205 Figura 1 - Ilustração do cen
Page 217 and 218:
207 Figura 2 - O Telescópio Espaci
Page 219 and 220:
209 interagem gravitacionalmente, a
Page 221 and 222:
211 e discos são conectados, é ba
Page 223:
213 uma correta separação entre a
Page 226 and 227:
216 Curriculum Vitæ omy Center (ES
Page 228 and 229:
218 Publications 8. c2d Spitzer-IRS
Page 230 and 231:
220 Thesis Acknowledgments Liesbeth
show all

Observational Constraints on The Evolution of Dust in ...

Create successful ePaper yourself

Delete template?

Save as template?