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J/ApJ/662/1067      Spitzer observations of sigma Orionis   (Hernandez+, 2007)

A Spitzer Space Telescope study of disks in the young σ Orionis cluster. Hernandez J., Hartmann L., Megeath T., Gutermuth R., Muzerolle J., Calvet N., Vivas A.K., Briceno C., Allen L., Stauffer J., Young E., Fazio G. <Astrophys. J., 662, 1067-1081 (2007)> =2007ApJ...662.1067H
ADC_Keywords: Clusters, open ; Infrared sources ; Photometry, infrared Keywords: infrared: stars - open clusters and associations: individual (sigma Orionis cluster) - planetary systems: protoplanetary disks - stars: formation - stars: pre-main sequence Abstract: We report new Spitzer Space Telescope observations, using the IRAC and MIPS instruments, of the young (∼3Myr) sigma Orionis cluster. We identify 336 stars as members of the cluster, using optical and near-infrared color-magnitude diagrams. Using the spectral energy distribution slopes in the IRAC spectral range, we place objects into several classes: non-excess stars, stars with optically thick disks (such as classical T Tauri stars), class I (protostellar) candidates, and stars with "evolved disks"; the last exhibit smaller IRAC excesses than optically thick disk systems. In general, this classification agrees with the location expected in IRAC-MIPS color-color diagrams for these objects. Description: We have observed a field of ∼1730arcmin2 in the sigma Orionis cluster using the four channels (3.6, 4.5, 5.8, and 8.0um) of the InfraRed Array Camer. In addition, 90% of this field was also observed using the 24um band of the Multiband Imaging Spectrometer for Spitzer. The IRAC observations presented here were taken on 2004 October 9. Optical magnitudes were obtained from the CIDA Equatorial Variability survey, which is being carried out using the QUEST I camera installed at the Jurgen Stock Telescope (a 1m Schmidt telescope) of the Venezuelan National Observatory at Llano del Hato. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table1.dat 117 336 Members of the σ Orionis Cluster table2.dat 117 133 Uncertain members of the σ Orionis Cluster
See also: J/A+A/419/249 : RJHKs photometry of sigma Ori low-mass stars (Scholz+, 2004) J/AJ/128/2316 : BVRIJHKs photometry in sigma Ori cluster (Sherry+, 2004) J/AN/325/740 : Astrophysical supplements to ASCC-2.5 (Kharchenko+, 2004) J/AN/325/705 : RIJHKs of low-mass stars in sigma Ori (Bejar+, 2004) J/AJ/129/907 : New Ori OB1 members (Briceno+, 2005) J/MNRAS/356/89 : sigma Ori low-mass stars (Kenyon+, 2005) J/MNRAS/356/1583 : RV of sigma Ori low-mass candidate memb. (Burningham+, 2005) J/A+A/446/501 : XMM observations of sigma Ori cluster (Franciosini+, 2006) J/A+A/466/917 : Brightest stars of sigma Orionis cluster (Caballero+, 2007) J/A+A/478/667 : The Mayrit catalogue (Caballero, 2008) J/A+A/488/167 : Low-mass stars in σ Ori and λ Ori (Sacco+ 2008) J/MNRAS/385/2210 : Spectroscopy around lam Ori and sig Ori (Maxted+, 2008) J/A+A/493/931 : Sigma Ori MAD observations (Bouy+, 2009) Byte-by-byte Description of file: table[12].dat
Bytes Format Units Label Explanations
1- 4 I4 --- [HHM2007] Identification number 6- 13 F8.5 deg RAdeg Right Ascension in decimal degrees (J2000) 15- 22 F8.5 deg DEdeg Declination in decimal degrees (J2000) 24- 28 F5.2 mag 3.6mag Spitzer/IRAC 3.6 micron band magnitude 30- 33 F4.2 mag e_3.6mag Uncertainty in 3.6mag 35- 39 F5.2 mag 4.5mag Spitzer/IRAC 4.5 micron band magnitude 41- 44 F4.2 mag e_4.5mag Uncertainty in 4.5mag 46- 50 F5.2 mag 5.8mag Spitzer/IRAC 5.8 micron band magnitude 52- 55 F4.2 mag e_5.8mag Uncertainty in 5.8mag 57- 61 F5.2 mag 8.0mag Spitzer/IRAC 8.0 micron band magnitude 63- 66 F4.2 mag e_8.0mag Uncertainty in 8.0mag 68- 72 F5.2 mag 24mag ? Spitzer/MIPS 24.0 micron band magnitude 74- 77 F4.2 mag e_24mag ? Uncertainty in 24.0mag 79- 83 F5.2 mag Vmag ? The V band magnitude (only for table1) 85- 88 F4.2 mag e_Vmag ? Uncertainty in Vmag (only for table1) 90 A1 --- r_Vmag Reference (only for table1) (1) 92 I1 --- V [0/1]? 1=variable, 0=non-variable (table1 only) 94 I1 --- X [0/1]? 1=X-ray emission (able1 only) 96-101 A6 --- Disk Disk classification (4) 103 I1 --- f_Disk [1/6]? Discrepancy in disk classification (5) 105-117 A13 --- Refs Known member reference(s) (only for table1) (1)
Note (1): References as follows: q = CIDA survey 1 = Barrado y Navascues et al. (2003A&A...404..171B) 2 = Bejar et al. (1999ApJ...521..671B) 3 = Bejar et al. (2001ApJ...556..830B) 4 = Bejar et al. (2004, Cat. J/AN/325/705) 5 = Burningham et al. (2005, Cat. J/MNRAS/356/1583) 6 = Kenyon et al. (2005, Cat. J/MNRAS/356/89) 7 = Kharchenko et al. (2004, Cat. J/AN/325/740) 8 = Oliveira et al. (2006MNRAS.369..272O) 9 = Sherry et al. (2004, Cat. J/AJ/128/2316) 10 = Scholz & Eisloffel (2004, Cat. J/A+A/419/249) 11 = Zapatero Osorio et al. (2002A&A...384..937Z) 12 = Jeffries et al. (2006MNRAS.371L...6J) Note (4): Disk class as follows: III = diskless II = thick disk I = class I candidate EV = evolved disk TD = transition disk candidate DD = Debris disk candidate Note (5): Flag on Disk as follows: 1 = Classified as III in Sect. 4.2 (systems have essentially no inner disk emission, with α←2.56) 2 = Classified as EV in Sect. 4.2 (evolved disks, -2.56≲α←1.8) 3 = Classified as II in Sect. 4.2 (systems with α<0) 4 = Classified as I in Sect. 4.2 (systems with α>0) 5 = Possible giant in the J-H versus H-K color-color diagram. 6 = Radial velocity consistent for stars in the older population (Jeffries et al., 2006MNRAS.371L...6J)
History: From electronic version of the journal
(End) Greg Schwarz [AAS], Patricia Vannier [CDS] 22-May-2009
The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line

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