J/A+A/542/A66 YSOs in 9 LMC star forming regions (Carlson+, 2012)
Identifying young stellar objects in nine Large Magellanic Cloud star forming
regions.
Carlson L.R., Sewilo M., Meixner M., Romita K. A., Lawton B.
<Astron. Astrophys. 542, A66 (2012)>
=2012A&A...542A..66C 2012A&A...542A..66C
ADC_Keywords: Magellanic Clouds ; YSOs ; Photometry, UBVRI ;
Photometry, infrared ; Cross identifications
Keywords: stars: formation - stars: protostars - ISM: HII regions -
ISM: photon-dominated region (PDR) - galaxies: Magellanic Clouds -
galaxies: star clusters: general
Abstract:
We introduce a new set of selection criteria for the identification of
infrared bright young stellar object (YSO) candidates and apply them
to nine HII regions in the Large Magellanic Cloud (LMC), focusing
particularly on lower mass candidates missed by most surveys. Data are
from the Spitzer Space Telescope legacy program SAGE (Surveying the
Agents of Galaxy Evolution; Meixner et al. 2006, Cat. J/AJ/132/2268,
see also II/305), combined with optical photometry from the Magellanic
Clouds Photometric Survey (MCPS; Zaritsky et al. 1997AJ....114.1002Z 1997AJ....114.1002Z)
and near-infrared photometry from the InfraRed Survey Facility (IRSF;
Kato et al. 2007, Cat. II/288). We choose regions of diverse physical
size, star formation rates (SFRs), and ages. We also cover a wide
range of locations and surrounding environments in the LMC. These
active star-forming regions are LHA 120-N 11, N 44, N 51, N 105, N
113, N 120, N 144, N 160, and N 206. Some have been well-studied
(e.g., N11, N44, N160) in the past, while others (e.g., N51, N144)
have received little attention. We identify 1045 YSO candidates,
including 918 never before identified and 127 matching previous
candidate lists. We characterize the evolutionary stage and physical
properties of each candidate using the spectral energy distribution
(SED) fitter of Robitaille et al. (2007ApJS..169..328R 2007ApJS..169..328R) and estimate
mass functions and SFRs for each region.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 234 1045 Well-fit YSO fluxes
table2.dat 334 1370 *YSO candidate magnitudes all lists
table3.dat 229 1419 List matching (all matched within 1arcsec)
table5.dat 224 1045 Well-fit YSO physical parameters derived from
SED fitting
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Note on table2.dat: Sources classified as Transition or Multiple objects by
Romita et al. (2010ApJ..721..357R) are not included.
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See also:
II/288 : IRSF Magellanic Clouds Point Source Catalog (Kato+ 2007)
II/305 : SAGE LMC and SMC IRAC Source Catalog (IPAC 2009)
J/AJ/132/2268 : SAGE calibration stars (Meixner+, 2006)
J/AJ/136/18 : LMC SAGE. New candidate YSOs (Whitney+, 2008)
J/ApJS/184/172 : High- and intermediate-mass YSOs in the LMC (Gruendl+, 2009)
J/ApJ/695/511 : Young massive stars in LHA 120-N 44 (Chen+, 2009)
J/ApJ/699/150 : Massive YSOs in LMC spectral classifications (Seale+, 2009)
J/MNRAS/411/1597 : LMC point source classification in SAGE-Spec (Woods+, 2011)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 4 A4 --- Region Region, NNNN (G1)
6- 14 F9.6 deg RAdeg Right ascension in decimal degrees (J2000)
16- 25 F10.6 deg DEdeg Declination in decimal degrees (J2000)
27- 36 A10 --- --- [SSTISAGEMA]
38- 56 A19 --- SAGE SAGE designation (JHHMMSS.ss+DDMMSS.s) (G2)
58- 63 F6.4 mJy FU ?=9.9999 Optical flux in U band (G3)
65- 70 F6.4 mJy e_FU ?=9.9999 rms uncertainty on FU
72- 77 F6.4 mJy FB ?=9.9999 Optical flux in B band (G3)
79- 84 F6.4 mJy e_FB ?=9.9999 rms uncertainty on FB
86- 91 F6.4 mJy FV ?=9.9999 Optical flux in V band (G3)
93- 98 F6.4 mJy e_FV ?=9.9999 rms uncertainty on FB
100-105 F6.4 mJy FI ?=9.9999 Optical flux in I band (G3)
107-112 F6.4 mJy e_FI ?=9.9999 rms uncertainty on FI
114-119 F6.4 mJy FJ ?=9.9999 Near-infrared flux in J band (G4)
121-126 F6.4 mJy e_FJ ?=9.9999 rms uncertainty on FJ
128-133 F6.4 mJy FH ?=9.9999 Near-infrared flux in H band (G4)
135-140 F6.4 mJy e_FH ?=9.9999 rms uncertainty on FH
142-147 F6.4 mJy FK ?=9.9999 Near-infrared flux in K band (G4)
149-154 F6.4 mJy e_FK ?=9.9999 rms uncertainty on FK
156-162 F7.4 mJy F3.6 ?=9.9999 Spitzer/IRAC flux in 3.6um band
164-169 F6.4 mJy e_F3.6 ?=9.9999 rms uncertainty on F3.6
171-177 F7.4 mJy F4.5 ?=9.9999 Spitzer/IRAC flux in 4.5um band
179-184 F6.4 mJy e_F4.5 ?=9.9999 rms uncertainty on F4.5
186-192 F7.4 mJy F5.8 ?=9.9999 Spitzer/IRAC flux in 5.8um band
194-199 F6.4 mJy e_F5.8 ?=9.9999 rms uncertainty on F5.8
201-207 F7.4 mJy F8.0 ?=9.9999 Spitzer/IRAC flux in 8.0um band
209-214 F6.4 mJy e_F8.0 ?=9.9999 rms uncertainty on F8.0
216-224 F9.4 mJy F24 ?=9.9999 Spitzer/MIPS flux in 24um band
226-232 F7.4 mJy e_F24 ?=9.9999 rms uncertainty on F24
234 I1 --- PAH [0/2] PAH flag (1)
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Note (1): Sources meeting the PAH color-selection criteria mentioned in
Sect. 3.2 are flagged as 1 or 2 as follows:
1 = error bars have been increased on 3.6, 5.8, and 8.0um fluxes
in SED fitting
2 = 24um flux is available, and we use 5.8 and 8.0um as upper limits.
We retain the original error bars in the table.
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Byte-by-byte Description of file: table2.dat
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Bytes Format Unit Label Explanations
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1- 4 A4 --- Region Region, NNNN (G1)
6- 16 F11.8 deg RAdeg Right ascension in decimal degrees (J2000)
18- 29 F12.8 deg DEdeg Declination in decimal degrees (J2000)
31- 40 A10 --- Match "SSTISAGEMA", "NONE" or "POOR MATCH" (2)
42- 60 A19 --- SAGE SAGE name, if match (G2)
62- 90 A29 --- W08 whitney et al. (2008AJ....136...18W 2008AJ....136...18W) designation,
sstisage1c jhhmmss.ss+DDMMSS.s
92-110 A19 --- GC09 gruendl & chu (2009ApJS..184..172G 2009ApJS..184..172G)
designation, yhhmmSS.ss+DDMMSS.s
([gc2009] jhhmmss.ss+DDMMSS.s in Simbad)
112-130 A19 --- S09 seale et al. (2009apJ...699..150S 2009apJ...699..150S) designation,
yhhmmss.ss+ddmmss.s
132-175 A44 --- OName other designation(s) (G5)
177 I1 --- C12WF [0/2] well-fit yso source (1=ok) (G6)
179-184 F6.3 mag Umag ?=99.999 optical u magnitude (G3)
186-190 F5.3 mag e_Umag ?=9.999 rms uncertainty on Umag (G3)
192-197 F6.3 mag Bmag ?=99.999 optical b magnitude (G3)
199-203 F5.3 mag e_Bmag ?=9.999 rms uncertainty on Bmag (G3)
205-210 F6.3 mag Vmag ?=99.999 optical v magnitude (G3)
212-216 F5.3 mag e_Vmag ?=9.999 rms uncertainty on Vmag (G3)
218-223 F6.3 mag Imag ?=99.999 optical i magnitude (G3)
225-229 F5.3 mag e_Imag ?=9.999 rms uncertainty on Imag (G3)
231-235 F5.2 mag Jmag ?=99.99 near-infrared J magnitude (G4)
237-240 F4.2 mag e_Jmag ?=9.99 rms uncertainty on Jmag (G4)
242-246 F5.2 mag Hmag ?=99.99 near-infrared H magnitude (G4)
248-251 F4.2 mag e_Hmag ?=9.99 rms uncertainty on Hmag (G4)
253-257 F5.2 mag Kmag ?=99.99 near-infrared K magnitude (G4)
259-262 F4.2 mag e_Kmag ?=9.99 rms uncertainty on Kmag (G4)
264-269 F6.3 mag [3.6] ?=99.999 Spitzer/IRAC 3.6um magnitude (2)
271-275 F5.3 mag e_[3.6] ?=9.999 rms uncertainty on [3.6] (2)
277-282 F6.3 mag [4.5] ?=99.999 Spitzer/IRAC 4.5um magnitude (2)
284-288 F5.3 mag e_[4.5] ?=9.999 rms uncertainty on [4.5] (2)
290-295 F6.3 mag [5.8] ?=99.999 Spitzer/IRAC 5.8um magnitude (2)
297-301 F5.3 mag e_[5.8] ?=9.999 rms uncertainty on [5.8] (2)
303-308 F6.3 mag [8.0] ?=99.999 Spitzer/IRAC 8.0um magnitude (2)
310-314 F5.3 mag e_[8.0] ?=9.999 rms uncertainty on [8.0] (2)
316-321 F6.3 mag [24] ?=99.999 Spitzer/MIPS 24um magnitude (2)
323-327 F5.3 mag e_[24] ?=9.999 rms uncertainty on [24] (2)
329 I1 --- Na number of α color-criteria met
331 I1 --- Nb number of β color-criteria met
333-334 I2 --- Set [0/10] set number
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Note (2): listed as "None" or "poor match" where no SAGE source matches
other candidate or source is extended and has insufficient SAGE photometry;
in these cases, photometry is taken from original list.
For matching SAGE sourcesn "Sstisagema" followed by the SAGE name
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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- 4 A4 --- Region region, nnnn (g1)
6- 15 F10.7 deg RAdeg right ascension in decimal degrees (J2000)
17- 27 F11.7 deg DEdeg declination in decimal degrees (J2000)
29- 38 A10 --- Match Match "SSTISAGEMA", "NONE" or "POOR MATCH" (3)
40- 58 A19 --- SAGE SAGE name in case of match (G2)
60- 88 A29 --- W08 Whitney et al. (2008AJ....136...18W 2008AJ....136...18W) designation,
SSTISAGE1C JHHMMSS.ss+DDMMSS.s
90- 93 I4 --- W08N ?=0 W08 Number, [WSI2008] NNNN
95-113 A19 --- GC09 Gruendl & Chu (2009ApJS..184..172G 2009ApJS..184..172G)
designation, YHHMMSS.ss+DDMMSS.s
([GC2009] JHHMMSS.ss+DDMMSS.s in Simbad)
115-133 A19 --- S09 Seale et al. (2009ApJ...699..150S 2009ApJ...699..150S) designation,
YHHMMSS.ss+DDMMSS.s
135-178 A44 --- OName Other designation(s) (G5)
180 I1 --- C12WF [0/2] Well-fit YSO source (1=ok) (G6)
182-187 A6 --- C12cl YSO evolutionary stage from SED fitting (4)
189-194 A6 --- W08cl W08 classification (5)
196-206 A11 --- GC09cl GC09 classification (6)
208-210 A3 --- S09Gr S09 group (7)
212-229 A18 --- OCl Other classifications
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Note (3): listed as "None" or "Poor Match" where no SAGE source matches
other candidate or source is extended and has insufficient SAGE photometry.
Note (4): "ambFit" with C12WF=2 where fit by YSO and non-YSO models
Note (5): Whitney et al. (2008AJ....136...18W 2008AJ....136...18W) classification:
YSO or high probability YSO (YSO_hp)
Note (6): Gruendl & Chu (2009ApJS..184..172G 2009ApJS..184..172G) classification:
probableYSO, possibleYSO or definiteYSO
Note (7): Seale et al. (2009ApJ..699..150S) spectroscopic groups:
S = YSOs with strong silicate absorption
P = YSOs with strong PAH emission
E = YSOs with fine-structure emission
SE = YSOs with strong silicate absorption and fine-structure emission
PE = YSOs with strong PAH and and fine-structure emission
F = YSOs with relatively featureless spectra
O = non-embedded sources
ERO = non-embedded sources
B = non-embedded sources
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Byte-by-byte Description of file: table5.dat
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Bytes Format Units Label Explanations
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1- 4 A4 --- Region Region, NNNN (G1)
6- 13 F8.5 deg RAdeg Right ascension in decimal degrees (J2000)
15- 23 F9.5 deg DEdeg Declination in decimal degrees (J2000)
25- 34 A10 --- --- [SSTISAGEMA]
36- 54 A19 --- SAGE SAGE designation (JHHMMSS.ss+DDMMSS.s) (G2)
56- 60 F5.2 --- chi2min χ2/pt of best fit
62- 66 F5.2 --- chi2max χ2/pt of worst considered fit
68- 71 I4 --- nfits Number of well-fit SEDs
73- 77 F5.2 Msun M*Bf Stellar mass of best fit model
79- 83 F5.2 Msun M*Av Average stellar mass of models
85- 88 F4.2 Msun e_M*Av Standard deviation of average stellar mass
90- 98 F9.2 Lsun L*Bf Luminosity of best fit model
100-108 F9.2 Lsun L*Av Average luminosity of models
110-117 F8.2 Lsun e_L*Av Standard deviation of luminosity
119-128 E10.4 Msun/yr dM/dtBf Disk accretion rate of best fit model
130-139 E10.4 Msun/yr dM/dtAv Average accretion rate of models
141-150 E10.4 Msun/yr e_dM/dtAv Standard deviation of accretion rate
152-161 E10.4 Msun MdBf Disk mass of best fit model
163-172 E10.4 Msun MdAv Average disk mass of models
174-183 E10.4 Msun e_MdAv Standard deviation of disk mass
185-194 E10.4 Msun MeBf Envelope mass of best fit model
196-205 E10.4 Msun MeAv Average envelope mass of models
207-216 E10.4 Msun e_MeAv Standard deviation of envelope mass
218-220 A3 --- cl.Bf Evolutionary stage of best fit model
222-224 A3 --- cl.Av Average evolutionary stage
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Global notes:
Note (G1): Regions are LHA 120-N 11, LHA 120-N 44, LHA 120-N 51, LHA 120-N 105,
LHA 120-N 113, LHA 120-N 120, LHA 120-N 144, LHA 120-N 160, and LHA 120-N 206
(Henize, 1956ApJS....2..315H 1956ApJS....2..315H).
Note (G2): Designations and infrared fluxes are from the Spitzer Space Telescope
Legacy Program SAGE (Surveying the Agents of Galaxy Evolution; Meixner et al.,
2006, Cat. II/305) "Single Frame + Mosaic Photometry Archive" as described in
the documentation on
http://irsa.ipac.caltech.edu/data/SPITZER/SAGE/
Note (G3): Optical fluxes and magnitudes are from the Magellanic Clouds
Photometric Survey (MCPS; Zaritsky et al., 1997AJ....114.1002Z 1997AJ....114.1002Z) matched within
1arcsec of infrared YSO candidates
Note (G4): Near-infrared fluxes and magnitudes are from Kato et al.
(2007PASJ..59..615K, Cat. II/288) matched within 1arcsec of infrared YSO
candidates.
Note (G5): Designations (preceded by first author name) from
Chen et al. (2009ApJ...695..511C 2009ApJ...695..511C) in N44, (2010ApJ..721..1206C 2010ApJ..721..1206C) in N160
Chen_HHMMSS.s+DDMMSS.s, [CCG2009] JHHMMSS.s+DDMMSS.s in Simbad
Romita et al. (2010ApJ...721..357R 2010ApJ...721..357R) in N206, Romita_YNNN
Fleener et al. (2010AJ....139..158F 2010AJ....139..158F) in N160, [FPC2010] JHHMMSS.ss+DDMMSS.s
Matches to spectroscopic YSOs from
Shimonishi et al. (2008ApJ...686L..99S 2008ApJ...686L..99S), denoted AKARI_JHHMMSS+DDMMSS,
Woods et al. (2011MNRAS.411.1597W 2011MNRAS.411.1597W), Woods_JHHMMSS.ss+DDMMSS.s
Note (G6): Whether we consider the source a well-fit YSO as follows:
0 = not well-fit
1 = well-fit and described in Table 5
2 = well-fit but also fit as non-YSO
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Acknowledgements:
Lynn Redding Carlson, carlson(at)strw.leidenuniv.nl
(End) Lynn Redding Carlson [Leiden Obs.], Patricia Vannier [CDS] 16-Apr-2012