J/A+A/518/L73 Youngest massive protostars in the LMC (Sewilo+, 2010)
The youngest massive protostars in the LMC.
Sewilo M., Indebetouw R., Carlson L.R., Whitney B., Chen C.-H.R.,
Meixner M., Robitaille T., van Loon J.T., Oliveira J.M., Churchwell E.,
Simon J.D., Hony S., Panuzzo P., Sauvage M., Roman-Duval J., Gordon K.,
Engelbracht C., Misselt K., Okumura K., Beck T., Hora J., Woods P.M.
<Astron. Astrophys. 518, L73 (2010)>
=2010A&A...518L..73S 2010A&A...518L..73S
ADC_Keywords: Magellanic Clouds ; Protostars ; YSOs ; Photometry, infrared ;
Photometry, millimetric/submm
Keywords: stars: formation - stars: protostars - Magellanic Clouds
Abstract:
We demonstrate the unique capabilities of Herschel to study very young
luminous extragalactic young stellar objects (YSOs) by analyzing a
central strip of the Large Magellanic Cloud obtained through the
HERITAGE Science Demonstration Program. We combine PACS 100 and 160,
and SPIRE 250, 350, and 500um photometry with 2MASS (1.25-2.17um) and
Spitzer IRAC and MIPS (3.6-70um) to construct complete spectral energy
distributions (SEDs) of compact sources. From these, we identify 207
candidate embedded YSOs in the observed region, ∼40% never-before
identified. We discuss their position in far-infrared color-magnitude
space, comparing with previously studied, spectroscopically confirmed
YSOs and maser emission. All have red colors indicating massive cool
envelopes and great youth. We analyze four example YSOs, determining
their physical properties by fitting their SEDs with radiative
transfer models. Fitting full SEDs including the Herschel data
requires us to increase the size and mass of envelopes included in the
models. This implies higher accretion rates (greater or equal to
10-4M☉/yr), in agreement with previous outflow studies of
high-mass protostars. Our results show that Herschel provides reliable
longwave SEDs of large samples of high-mass YSOs; discovers the
youngest YSOs whose SEDs peak in Herschel bands; and constrains the
physical properties and evolutionary stages of YSOs more precisely
than was previously possible.
Description:
This table contains the names, coordinates, 2MASS (JHKs), Spitzer
(IRAC 3.6, 4.5, 5.8, 8.0um; MIPS 24, 70um), and Herschel (PACS 100,
160; SPIRE 250, 350, 500um) fluxes for 4 embedded YSOs analyzed in the
paper. Source fluxes were determined by aperture photometry on 2MASS,
Spitzer, and Herschel images using apertures scaled to the
instrumental resolution. Details on aperture sizes and aperture
corrections can be found in Sect. 2 of the paper. The last column of
the table gives alternative names of the sources from literature.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 192 4 Spitzer and Herschel fluxes for YSOs discussed
in Sect. 5
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See also:
J/ApJS/184/172 : High- and intermediate-mass YSOs in the LMC (Gruendl+, 2009)
J/ApJ/699/150 : Spectral analysis of massive YSOs in LMC (Seal+, 2009)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 5 A5 --- Name Source name (YSO-N)
7- 8 I2 h RAh Right ascension (J2000)
10- 11 I2 min RAm Right ascension (J2000)
13- 17 F5.2 s RAs Right ascension (J2000)
19 A1 --- DE- Declination sign (J2000)
20- 21 I2 deg DEd Declination (J2000)
23- 24 I2 arcmin DEm Declination (J2000)
26- 29 F4.1 arcsec DEs Declination (J2000)
31 A1 --- l_FJ Limit flag on FJ
32- 34 F3.1 mJy FJ 2MASS J band flux
36- 38 F3.1 mJy e_FJ ? rms uncertainty in FJ
40 A1 --- l_FH Limit flag on FH
41- 43 F3.1 mJy FH 2MASS H band flux
45- 47 F3.1 mJy e_FH ? rms uncertainty in FH
49 A1 --- l_FKs Limit flag on FKs
50- 52 F3.1 mJy FKs 2MASS Ks band flux
54- 56 F3.1 mJy e_FKs ? rms uncertainty in FKs
58- 62 F5.2 mJy F3.6 Spitzer/IRAC 3.6 micron band flux
64- 67 F4.2 mJy e_F3.6 rms uncertainty in F3.6um
69- 73 F5.2 mJy F4.5 Spitzer/IRAC 4.5 micron band flux
75- 78 F4.2 mJy e_F4.5 rms uncertainty in F4.5um
80 A1 --- l_F5.8 Limit flag on F5.8um
81- 83 I3 mJy F5.8 Spitzer/IRAC 5.8 micron band flux
85- 86 I2 mJy e_F5.8 ? rms uncertainty in F5.8um
88 A1 --- l_F8.0 Limit flag on F8.0um
89- 91 I3 mJy F8.0 Spitzer/IRAC 8.0 micron band flux
93- 94 I2 mJy e_F8.0 ? rms uncertainty in F8.0um
96 A1 --- l_F24 Limit flag on F24um
97-100 I4 mJy F24 Spitzer/MIPS 24 micron band flux
102-103 I2 mJy e_F24 ? rms uncertainty in F24um
105-109 I5 mJy F70 Spitzer/MIPS 70 micron band flux
111-114 I4 mJy e_F70 rms uncertainty in F70um
116-120 I5 mJy F100 Herschel/PACS 100 micron band flux
122-125 I4 mJy e_F100 rms uncertainty in F100um
127-131 I5 mJy F160 Herschel/PACS 160 micron band flux
133-137 I5 mJy e_F160 rms uncertainty in F160um
139-143 I5 mJy F250 Herschel/SPIRE 250 micron band flux
145-148 I4 mJy e_F250 rms uncertainty in F250um
150-154 I5 mJy F350 Herschel/SPIRE 350 micron band flux
156-159 I4 mJy e_F350 rms uncertainty in F350um
161 A1 --- l_F500 Limit flag on F500um
162-165 I4 mJy F500 Herschel/SPIRE 500 micron band flux
167-169 I3 mJy e_F500 ? rms uncertainty in F500um
171-188 A18 --- OName Other names
190-192 A3 --- r_OName Reference for OName (1)
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Note (1): Reference as follows:
1 = Gruendl & Chu, 2009, Cat. J/ApJS/184/172
2 = Seale, Looney, Chu et al., 2009, Cat. J/ApJ/699/150
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Acknowledgements:
Marta Sewilo, mmsewilo(at)stsci.edu
(End) Marta Sewilo [STScI], Patricia Vannier [CDS] 27-Apr-2010