J/AJ/136/18 LMC SAGE. New candidate YSOs (Whitney+, 2008)
Spitzer SAGE survey of the Large Magellanic Cloud.
III. Star formation and ∼1000 new candidate young stellar objects.
Whitney B.A., Sewilo M., Indebetouw R., Robitaille T.P., Meixner M.,
Gordon K., Meade M.R., Babler B.L., Harris J., Hora J.L., Bracker S.,
Povich M.S., Churchwell E.B., Engelbracht C.W., For B.-Q., Block M.,
Misselt K., Vijh U., Leitherer C., Kawamura A., Blum R.D., Cohen M.,
Fukui Y., Mizuno A., Mizuno N., Srinivasan S., Tielens A.G.G.M., Volk K.,
Bernard J.-P., Boulanger F., Frogel J.A., Gallagher J., Gorjian V.,
Kelly D., Latter W.B., Madden S., Kemper F., Mould J.R., Nota A., Oey M.S.,
Olsen K.A., Onishi T., Paladini R., Panagia N., Perez-Gonzalez P.,
Reach W., Shibai H., Sato S., Smith L.J., Staveley-Smith L., Ueta T.,
Van Dyk S., Werner M., Wolff M., Zaritsky D.
<Astron. J., 136, 18-43 (2008)>
=2008AJ....136...18W 2008AJ....136...18W
ADC_Keywords: Magellanic Clouds ; YSOs ; Photometry, infrared
Keywords: circumstellar matter - galaxies: dwarf - infrared: stars -
Magellanic Clouds - stars: formation - stars: pre-main sequence
Abstract:
We present ∼1000 new candidate Young Stellar Objects (YSOs) in the
Large Magellanic Cloud selected from Spitzer Space Telescope data, as
part of the Surveying the Agents of a Galaxy's Evolution (SAGE) Legacy
program. The YSOs, detected by their excess infrared (IR) emission,
represent early stages of evolution, still surrounded by disks and/or
infalling envelopes. Previously, fewer than 20 such YSOs were known.
The candidate YSOs were selected from the SAGE Point Source Catalog
from regions of color-magnitude space least confused with other
IR-bright populations.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 191 1197 YSO candidates: fluxes
table2.dat 146 1197 YSO candidates: magnitudes
table3.dat 85 19 Previously known YSOs
table4.dat 119 19 *Previously known YSOs: magnitudes
table5.dat 112 299 Physical parameters of selected YSO candidates
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Note on table4.dat: Magnitudes from the SAGE Catalog are given where available.
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See also:
J/AJ/132/2268 : SAGE calibration stars (Meixner+, 2006)
J/AJ/135/726 : Spitzer SAGE observations of LMC PNe (Hora+, 2008)
J/AJ/136/18 : LMC SAGE. New candidate YSOs (Whitney+, 2008)
J/PASP/122/683 : SAGE-Spec Spitzer legacy program (Kemper+, 2010)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 4 I4 --- Seq Running identification number,
<[WSI2008] NNNN> in Simbad
6- 15 A10 --- --- [SSTISAGE1C]
16- 34 A19 --- SSTISAGE1C IRAC designation, JHHMMSS.ss+DDMMSS.s
37- 45 F9.6 deg RAdeg Right Ascension in decimal degrees (J2000)
47- 56 F10.6 deg DEdeg Declination in decimal degrees (J2000)
58- 62 F5.3 arcsec Off ?=- IRAC/MIPS position offset
64- 70 F7.2 mJy FJ ?=-999.9 2MASS J band flux density
72- 78 F7.2 mJy e_FJ ?=-999.9 Error in FJ
80- 86 F7.2 mJy FH ?=-999.9 2MASS H band flux density
88- 94 F7.2 mJy e_FH ?=-999.9 Error in FH
96-102 F7.2 mJy FKs ?=-999.9 2MASS Ks band flux density
104-110 F7.2 mJy e_FKs ?=-999.9 Error in FKs
112-118 F7.2 mJy F3.6 ?=-999.9 Spitzer/IRAC 3.6um band flux density
120-126 F7.2 mJy e_F3.6 ?=-999.9 Error in F3.6
128-134 F7.2 mJy F4.5 ?=-999.9 Spitzer/IRAC 4.5um band flux density
136-142 F7.2 mJy e_F4.5 ?=-999.9 Error in F4.5
144-150 F7.2 mJy F5.8 ?=-999.9 Spitzer/IRAC 5.8um band flux density
152-158 F7.2 mJy e_F5.8 ?=-999.9 Error in F5.8
160-166 F7.2 mJy F8.0 ?=-999.9 Spitzer/IRAC 8.0um band flux density
168-174 F7.2 mJy e_F8.0 ?=-999.9 Error in F8.0
176 A1 --- l_F24 Limit flag on F24
177-183 F7.2 mJy F24 ?=-999.9 Spitzer/MIPS 24um band flux density
185-191 F7.2 mJy e_F24 ?=-999.9 Error in F24
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 4 I4 --- Seq Running identification number,
<[WSI2008] NNNN> in Simbad
6- 14 F9.6 deg RAdeg Right Ascension in decimal degrees (J2000)
16- 25 F10.6 deg DEdeg Declination in decimal degrees (J2000)
27- 32 F6.3 mag Jmag ?=99.999 2MASS J band magnitude
34- 39 F6.3 mag e_Jmag ?=99.999 Error in Jmag
41- 46 F6.3 mag Hmag ?=99.999 2MASS H band magnitude
48- 53 F6.3 mag e_Hmag ?=99.999 Error in Hmag
55- 60 F6.3 mag Ksmag ?=99.999 2MASS Ks band magnitude
62- 67 F6.3 mag e_Ksmag ?=99.999 Error in Ksmag
69- 74 F6.3 mag [3.6] ?=99.999 Spitzer/IRAC 3.6um band magnitude
76- 81 F6.3 mag e_[3.6] ?=99.999 Error in [3.6]
83- 88 F6.3 mag [4.5] ?=99.999 Spitzer/IRAC 4.5um band magnitude
90- 95 F6.3 mag e_[4.5] ?=99.999 Error in [4.5]
97-102 F6.3 mag [5.8] ?=99.999 Spitzer/IRAC 5.8um band magnitude
104-109 F6.3 mag e_[5.8] ?=99.999 Error in [5.8]
111-116 F6.3 mag [8.0] ?=99.999 Spitzer/IRAC 8.0um band magnitude
118-123 F6.3 mag e_[8.0] ?=99.999 Error in 8.0]
125 A1 --- l_[24] Limit flag on [24]
126-131 F6.3 mag [24] ?=99.999 Spitzer/MIPS 24um band magnitude
133-138 F6.3 mag e_[24] ?=99.999 Error in [24]
140-146 A7 --- Class Classification (1)
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Note (1): Classification code as follows:
YSO = Young Stellar Object
YSO_hp = high probability YSO (Section 3.4)
PN = Planetary Nebula
Evolved = this category includes Wolf-Rayet, Emission Line, post-AGB,
C-rich AGB stars, and Cepheids
galaxy = probable background galaxy
x-ray = SIMBAD identified x-ray source
SN87a = SN87a
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 18 A18 --- Name Source name
20 A1 --- n_Name Individual notes (1)
22- 23 I2 h RAh Right ascension (J2000)
25- 26 I2 min RAm Right ascension (J2000)
28- 32 F5.2 s RAs Right ascension (J2000)
34 A1 --- DE- Declination sign (J2000)
35- 36 I2 deg DEd Declination (J2000)
38- 39 I2 arcmin DEm Declination (J2000)
41- 44 F4.1 arcsec DEs Declination (J2000)
46- 55 A10 --- --- [SSTISAGE1C]
57- 75 A19 --- SSTISAGE1C IRAC designation (JHHMMSS.ss+DDMMSS.s)
77- 79 F3.1 arcsec Sep1 ? Separation IRAC/MIPS
80 A1 --- --- [/]
81- 83 F3.1 arcsec Sep2 ? Second separation IRAC/MIPS
85 I1 --- Ref Reference (G1)
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Note (1): Notes as follows:
a = P2 was resolved into two components by Testor et al.
(2006, Cat. J/A+A/453/517, resolution 0.2"):
N159A7-121 (alpha=05:39:41.96, delta=-69:46:11.99, J2000) and
N159A7-123 (alpha=05:39:41.90, delta=-69:46:11.52, J2000), both
classified as Class I YSOs.
b = The compact source N159A6 discovered by Testor et al.
(2006, Cat. J/A+A/453/517) consists of two objects contained
within a diameter of 0.5pc: an YSO N159A6-151 and a CHII/HII
region containing about five stars. At the IRAC resolution of 2"
(0.48pc at 50kpc), N159A6 will be either unresolved or only
slightly resolved.
c = LTS ("LMC T Tauri Star") J054427-692659 is the first
spectroscopically confirmed discovery of T Tauri star in the LMC
d = ELHC stands for EROS LMC HAe/Be Candidates Lamers et al.
(1999A&A...341..827L 1999A&A...341..827L). ELHC7 is a confirmed HAe/Be UX Orionis star.
e = de Wit et al. (2005A&A...432..619D 2005A&A...432..619D) suggested that the type of
variability of these sources could be interpreted as caused by
variable dust obscuration; thus it is possible that they are
pre-MS objects. However, these sources lack thermal dust
emission in the near IR. The circumstellar dust emission could
be revealed in the mid- or far IR; thus the observations at
these wavelengths are crucial to confirm that these objects are
in a pre-MS stage.
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 18 A18 --- Name Source name
21 A1 --- l_Jmag Limit flag on Jmag
22- 26 F5.2 mag Jmag ? 2MASS J magnitude
28- 31 F4.2 mag e_Jmag ? rms uncertainty in Jmag
32 A1 --- n_Jmag [b] Note (2)
34 A1 --- l_Hmag Limit flag on Hmag
35- 39 F5.2 mag Hmag ? 2MASS H magnitude
41- 44 F4.2 mag e_Hmag ? rms uncertainty in Hmag
45 A1 --- n_Hmag [b] Note (2)
47- 51 F5.2 mag Ksmag ? 2MASS Ks magnitude
53- 56 F4.2 mag e_Ksmag ? rms uncertainty in Ksmag
57 A1 --- n_Ksmag [b] Note (2)
59- 63 F5.2 mag [3.6] ? Spitzer/IRAC 3.6um magnitude
65- 68 F4.2 mag e_[3.6] ? rms uncertainty in [3.6]
69 A1 --- n_[3.6] [bc] Note (2)
71- 75 F5.2 mag [4.5] ? Spitzer/IRAC 4.5um magnitude
77- 80 F4.2 mag e_[4.5] ? rms uncertainty in [4.5]
81 A1 --- n_[4.5] [bc] Note (2)
83- 87 F5.2 mag [5.8] ? Spitzer/IRAC 5.8um magnitude
89- 92 F4.2 mag e_[5.8] ? rms uncertainty in [5.8]
93 A1 --- n_[5.8] [bc] Note (2)
95- 99 F5.2 mag [8.0] ? Spitzer/IRAC 8.0um magnitude
101-104 F4.2 mag e_[8.0] ? rms uncertainty in [8.0]
105 A1 --- n_[8.0] [bc] Note (2)
107 A1 --- l_[24] Limit flag on [24]
108-111 F4.2 mag [24] ? Spitzer/MIPS 24um magnitude
113-116 F4.2 mag e_[24] ? rms uncertainty in [24]
117 A1 --- n_[24] [bcd] Note (2)
119 I1 --- Ref References (G1)
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Note (2): Notes as follows:
b = Data from literature (see references below)
c = Magnitudes measured in this work using aperture photometry
d = Source saturated at 24um
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Byte-by-byte Description of file: table5.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 I4 --- Seq Running identification number,
<[WSI2008] NNNN> in Simbad
6- 15 A10 --- --- [SSTISAGE1C]
16- 34 A19 --- SSTISAGE1C IRAC designation, JHHMMSS.ss+DDMMSS.s
36- 39 F4.2 --- chi2 Minimum χ2 per datapoint
41- 43 I3 --- nfits Number of fits (1)
45- 49 F5.2 Msun M* ?=0 Average stellar mass
51- 54 F4.2 Msun e_M* ?=0 Standard deviation in M*
56- 63 E8.3 Lsun Lum ?=0 Average stellar luminosity
65- 72 E8.3 Lsun e_Lum ?=0 Standard deviation in Lum
74- 81 E8.3 Msun/yr Mdot ?=0 Average envelope infall rate
83- 90 E8.3 Msun/yr e_Mdot ?=0 Standard deviation in Mdot
92- 99 E8.3 Msun Mdisk ?=0 Average disk mass
101-108 E8.3 Msun e_Mdisk ?=0 Standard deviation in Mdisk
110-112 A3 --- Stage ?=0 Average evolutionary stage (2)
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Note (1): With cpd between cpdmin and cpdmin+1.
Note (2): Average evolutionary stage code as follows:
I = young embedded
II = optically thick disk
III = optically thin disk
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Global notes:
Note (G1): References as follows:
1 = Brandner et al. (2001AJ....122..858B 2001AJ....122..858B)
2 = Jones et al. (2005ApJ...620..731J 2005ApJ...620..731J)
3 = Testor et al. (2006, Cat. J/A+A/453/517)
4 = Epchtein et al. (1984A&A...140...67E 1984A&A...140...67E)
5 = van Loon et al. (2005MNRAS.364L..71V 2005MNRAS.364L..71V)
6 = Oliveira et al. (2006MNRAS.372.1509O 2006MNRAS.372.1509O)
7 = Chu et al. (2005ApJ...634L.189C 2005ApJ...634L.189C)
8 = Wichmann et al. (2001A&A...380L...9W 2001A&A...380L...9W)
9 = de Wit et al. (2005A&A...432..619D 2005A&A...432..619D), and references therein.
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History:
From electronic version of the journal
References:
Meixner et al., Paper I 2006AJ....132.2268M 2006AJ....132.2268M, Cat. J/AJ/132/2268
Blum et al., Paper II 2006AJ....132.2034B 2006AJ....132.2034B
Bernard et al., Paper IV 2008AJ....136..919B 2008AJ....136..919B
(End) Greg Schwarz [AAS], Patricia Vannier [CDS] 15-Jan-2011