J/ApJ/695/511 Young massive stars in LHA 120-N 44 (Chen+, 2009)
Spitzer view of young massive stars in the Large Magellanic Cloud H II
complex N 44.
Chen C.-H.R., Chu Y.-H., Gruendl R.A., Gordon K.D., Heitsch F.
<Astrophys. J., 695, 511-541 (2009)>
=2009ApJ...695..511C 2009ApJ...695..511C
ADC_Keywords: H II regions ; YSOs ; Photometry, infrared ; Photometry, UBVRI
Magellanic Clouds
Keywords: H II regions - infrared: stars - ISM: individual (N44) -
Magellanic Clouds - stars: formation - stars: pre-main sequence
Abstract:
The HII complex N44 in the Large Magellanic Cloud (LMC) provides an
excellent site to perform a detailed study of star formation in a mild
starburst, as it hosts three regions of star formation at different
evolutionary stages, and it is not as complicated and confusing as the
30 Doradus giant HII region. We have obtained Spitzer Space Telescope
observations and complementary ground-based 4m uBVIJK observations of
N44 to identify candidate massive young stellar objects (YSOs). We
further classify the YSOs into Types I, II, and III, according to
their spectral energy distributions (SEDs). In our sample of 60 YSO
candidates, ∼65% of them are resolved into multiple components or
extended sources in high-resolution ground-based images.
Description:
Our Spitzer observations of N44 were made with the InfraRed Array
Camera (IRAC) on 2005 March 27 and the Multiband Imaging Photometer
for Spitzer (MIPS) on 2005 April 7.
We obtained near-IR images in the J and Ks bands with the Infrared
Side Port Imager (ISPI) on the Blanco 4m telescope at Cerro Tololo
Inter-American Observatory (CTIO) on 2005 November 14-15.
We obtained the SDSS u and Johnson-Cousins BVI broadband images of N44
with the MOSAIC II CCD Imager on the CTIO Blanco 4m telescope on 2006
February 2.
Observations have been completed by archival data from HST and CTIO
0.9m telescope.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 183 17002 Multi-wavelength photometry of IRAC sources in N44
table5.dat 201 99 Multiwavelength photometry of YSO candidates
selected from CMD criteria
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See also:
II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
J/ApJS/184/172 : High- and intermediate-mass YSOs in the LMC (Gruendl+, 2009)
J/ApJ/678/200 : YSOs in N63 and N180 (Caulet+, 2008)
J/A+AS/123/455 : LH 47 UVBRI photometry (Will+ 1997)
J/ApJS/104/71 : UBV photometry of OB associations in LMC superbubbles (Oey
1996)
J/ApJ/452/210 : UBV photometry in LH 47/48 (Oey+ 1995)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 17 A17 --- [CCG2009] Source name (HHMMSS.s+DDMMSS.s -- J2000)
19- 26 F8.5 deg RAdeg Right Ascension in decimal degrees (J2000)
28- 36 F9.5 deg DEdeg Declination in decimal degrees (J2000)
38- 42 F5.2 mag Umag ? The U band magnitude
44- 47 F4.2 mag e_Umag ? Uncertainty in Umag
49- 53 F5.2 mag Bmag ? The B band magnitude
55- 58 F4.2 mag e_Bmag ? Uncertainty in Bmag
60- 64 F5.2 mag Vmag ? The V band magnitude
66- 69 F4.2 mag e_Vmag ? Uncertainty in Vmag
71- 75 F5.2 mag Imag ? The I band magnitude
77- 80 F4.2 mag e_Imag ? Uncertainty in Imag
82- 86 F5.2 mag Jmag ? 2MASS J band magnitude
88- 91 F4.2 mag e_Jmag ? Uncertainty in Jmag
93- 97 F5.2 mag Hmag ? 2MASS H band magnitude
99-102 F4.2 mag e_Hmag ? Uncertainty in Hmag
104-108 F5.2 mag Ksmag ? 2MASS KS band magnitude
110-113 F4.2 mag e_Ksmag ? Uncertainty in Kmag
115-119 F5.2 mag 3.6mag ? Spitzer/IRAC 3.6 micron band magnitude
121-124 F4.2 mag e_3.6mag ? Uncertainty in 3.6mag
126-130 F5.2 mag 4.5mag ? Spitzer/IRAC 4.5 micron band magnitude
132-135 F4.2 mag e_4.5mag ? Uncertainty in 4.5mag
137-141 F5.2 mag 5.8mag ? Spitzer/IRAC 5.8 micron band magnitude
143-146 F4.2 mag e_5.8mag ? Uncertainty in 5.8mag
148-152 F5.2 mag 8.0mag ? Spitzer/IRAC 8.0 micron band magnitude
154-157 F4.2 mag e_8.0mag ? Uncertainty in 8.0mag
159-163 F5.2 mag 24mag ? Spitzer/MIPS 24 micron band magnitude
164 A1 --- f_24mag [s] Indicates 24mag is saturated
166-169 F4.2 mag e_24mag ? Uncertainty in 24mag
171-175 F5.2 mag 70mag ? Spitzer/MIPS 70 micron band magnitude
177-180 F4.2 mag e_70mag ? Uncertainty in 70mag
182-183 I2 --- Ref [0/10] UBVI photometry reference flag (1)
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Note (1): Reference flag as follows:
0 = UBV from Chen, C.-H.R. 2007, PhD thesis, Univ. Illinois at
Urbana-Champaign.
10 = UBVI from MCPS (Magellanic Cloud Photometric Survey, Zaritsky et al.
2004AJ....128.1606Z 2004AJ....128.1606Z).
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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- 17 A17 --- [CCG2009] Source name, as in table2
19- 20 I2 --- No Ranking of the brightness at 8um
22- 26 F5.2 mag Umag ? The U band magnitude
28- 31 F4.2 mag e_Umag ? Uncertainty in Umag
33- 37 F5.2 mag Bmag ? The B band magnitude
39- 42 F4.2 mag e_Bmag ? Uncertainty in Bmag
44- 48 F5.2 mag Vmag ? The V band magnitude
50- 53 F4.2 mag e_Vmag ? Uncertainty in Vmag
55 A1 --- l_Imag Limit flag on Imag (1)
56- 60 F5.2 mag Imag ? The I band magnitude
62- 65 F4.2 mag e_Imag ? Uncertainty in Imag
67 A1 --- l_Jmag Limit flag on Jmag (1)
68- 72 F5.2 mag Jmag ? 2MASS J band magnitude
74- 77 F4.2 mag e_Jmag ? Uncertainty in Jmag
79- 83 F5.2 mag Hmag ? 2MASS H band magnitude
85- 88 F4.2 mag e_Hmag ? Uncertainty in Hmag
90 A1 --- l_Ksmag Limit flag on Ksmag (1)
91- 95 F5.2 mag Ksmag ? 2MASS KS band magnitude
97-100 F4.2 mag e_Ksmag ? Uncertainty in Ksmag
102 A1 --- l_3.6mag Limit flag on 3.6mag (1)
103-107 F5.2 mag 3.6mag ? Spitzer/IRAC 3.6 micron band magnitude
109-112 F4.2 mag e_3.6mag ? Uncertainty in 3.6mag
114 A1 --- l_4.5mag Limit flag on 4.5mag (1)
115-119 F5.2 mag 4.5mag ? Spitzer/IRAC 4.5 micron band magnitude
121-124 F4.2 mag e_4.5mag ? Uncertainty in 4.5mag
126-130 F5.2 mag 5.8mag ? Spitzer/IRAC 5.8 micron band magnitude
132-135 F4.2 mag e_5.8mag ? Uncertainty in 5.8mag
137-141 F5.2 mag 8.0mag ? Spitzer/IRAC 8.0 micron band magnitude
143-146 F4.2 mag e_8.0mag ? Uncertainty in 8.0mag
148 A1 --- l_24mag Limit flag on 24mag (1)
149-152 F4.2 mag 24mag ? Spitzer/MIPS 24 micron band magnitude
153 A1 --- f_24mag [s] Indicates 24mag is saturated
155-158 F4.2 mag e_24mag ? Uncertainty in 24mag
160 A1 --- l_70mag Limit flag on 70mag (1)
161-165 F5.2 mag 70mag ? Spitzer/MIPS 70 micron band magnitude
167-170 F4.2 mag e_70mag ? Uncertainty in 70mag
172-173 I2 --- Ref [0/11] IJHK photometry reference flag (2)
175-187 A13 --- Class Classification (3)
189-201 A13 --- Note Remark (3)
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Note (1): Measurements are the upper brightness limits as they include
fluxes from neighbors or backgrounds.
Note (2): Data used for IJHK photometry as follows:
0 = I from MCPS (Magellanic Cloud Photometric Survey, Zaritsky et al.
2004AJ....128.1606Z 2004AJ....128.1606Z) and JHK from 2MASS catalog (II/246),
10 = I from 4m Mosaic data and JHK from 2MASS catalog (II/246),
11 = I from 4m Mosaic data and JHK from 4m ISPI data.
Note (3): Abbreviations used:
D = diffuse emission,
DC = dark cloud,
DR = dusty region,
G = background galaxy,
mul = multiple,
MC = molecular cloud
N = nebula,
RN = reflection nebula,
S = star,
T1/2/3 = Type I/II/III YSO,
YSC = young star cluster
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 28-Apr-2011