B. A. Whitney 1, M. Sewilo 2, R. Indebetouw 3, T. P. Robitaille 4, M. Meixner 2, K. Gordon 5, M. R. Meade 6, B. L. Babler 6, J. Harris 5, J. L. Hora 7, S. Bracker 6, M. S. Povich 6, E. B. Churchwell 6, C. W. Engelbracht 5, B-Q For 5,8, M. Block 5, K. Misselt 5, U. Vijh 2, C. Leitherer 2, A. Kawamura 9, R. D. Blum 10, M. Cohen 11, Y. Fukui 9, A. Mizuno 9, N. Mizuno 9, S. Srinivasan 12, A. G. G. M. Tielens 13, K. Volk 14, J-P. Bernard 15, F. Boulanger 16, J. A. Frogel 17, J. Gallagher 6, V. Gorjian 18, D. Kelly 5, W. B. Latter 19, S. Madden 20, F. Kemper 21, J. R. Mould 10, A. Nota 2, M. S. Oey 22, K. A. Olsen 23, T. Onishi 9, R. Paladini 24, N. Panagia 2, P. Perez-Gonzalez 5, W. Reach 24, H. Shibai 9, S. Sato 9, L. J. Smith 2,25, L. Staveley-Smith 26, T. Ueta 27, S. Van Dyk 24, M. Werner 18, M. Wolff 1 and D. Zaritsky 5
1
Space Science Institute, 4750 Walnut St. Suite 205, Boulder, CO 80301, USA
2
Space Telescope Science Institute, 3700 San Martin Way, Baltimore, MD 21218, USA
3
Department of Astronomy, University of Virginia, P.O. Box 3818, Charlottesville, VA 22903, USA
4
School of Physics and Astronomy, University of St Andrews, North Haugh, KY16 9SS, St Andrews, UK
5
Steward Observatory, University of Arizona, 933 North Cherry Ave., Tucson, AZ 85719, USA
6
Department of Astronomy, 475 North Charter St., University of Wisconsin, Madison, WI 53706, USA
7
Center for Astrophysics, 60 Garden St., MS 67, Harvard University, Cambridge, MA 02138, USA
8
Department of Astronomy, University of Texas at Austin, 1 University Station, C1400, Austin, TX 78712, USA
9
Department of Astrophysics, Nagoya University, Chikusa-ku, Nagoya 464-8602, Japan
10
NOAO, P.O. Box 26732, Tucson AZ 85726-6732, USA
11
Radio Astronomy Laboratory, 601 Campbell Hall, University of California at Berkeley, Berkeley, CA 94720, USA
12
Department of Physics and Astronomy, Johns Hopkins University, Homewood Campus, Baltimore, MD 21218, USA
13
NASA Ames Research Center, SOFIA Office, MS 211-3, Moffet Field, CA 94035, USA
14
Gemini Observatory, 670 North A'ohuku Place, Hilo, HI 96720, USA
15
Centre d' Étude Spatiale des Rayonnements, CNRS, 9 av. du Colonel Roche, BP 4346, 31028 Toulouse, France
16
Astrophysique de Pari, Institute (IAP), CNRS UPR 341, 98bis, Boulevard Arago, Paris, F-75014, France
17
AURA, Inc., 1200 New York Ave. NW, Suite 350, Washington D.C. 20005, USA
18
Jet Propulsion Lab, 4800 Oak Grove Dr., MS 264-767, Pasadena, CA 91109, USA
19
Caltech, NASA Herschel Science Center, MS 100-22, Pasadena, CA 91125, USA
20
Service dAstrophysique CEA, Saclay, 91191 Gif Sur Yvette Cedex, France
21
Jodrell Bank Centre for Astrophysics, University of Manchester, M13 9PL, Manchester, UK
22
Department of Astronomy, University of Michigan, 830 Dennison Bldg., Ann Arbor, MI 48109, USA
23
Cerro Tololo Interamerican Observatory, Casilla 603, La Serena, Chile
24
Spitzer Science Center, California Institute of Technology, 220-6, Pasadena, CA, 91125, USA
25
Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT, UK
26
Australia Telescope National Facility, CSIRO, P.O. Box 76, Epping NSW 1710, Australia
27
Department of Physics and Astronomy, University of Denver, Denver, CO 80208, USA
bwhitney@spacescience.org wolff@spacescience.org sewilo@stsci.edu meixner@stsci.edu vijh@stsci.edu leitherer@stsci.edu nota@stsci.edu panagia@stsci.edu lsmith@stsci.edu remy@virginia.edu tr9@st-andrews.ac.uk kgordon@as.arizona.edu cengelbracht@as.arizona.edu biqing@email.arizona.edu kmisselt@as.arizona.edu pgperez@as.arizona.edu jharris@as.arizona.edu dkelly@as.arizona.edu dennis@fishingholes.as.arizona.edu meade@sal.wisc.edu brian@sal.wisc.edu ebc@astro.wisc.edu jsg@astro.wisc.edu povich@astro.wisc.edu s_bracker@hotmail.com jhora@cfa.harvard.edu biqing@astro.as.utexas.edu fukui@a.phys.nagoya-u.ac.jp kawamura@a.phys.nagoya-u.ac.jp mizuno@a.phys.nagoya-u.ac.jp norikazu@a.phys.nagoya-u.ac.jp ohnishi@a.phys.nagoya-u.ac.jp shibai@nagoya-u.jp ssato@z.phys.nagoya-u.ac.jp jmould@noao.edu rblum@noao.edu mcohen@astro.berkeley.edu sundar@pha.jhu.edu atielens@arc.nasa.gov kvolk@gemini.edu Jean-Philippe.Bernard@cesr.fr Francois.Boulanger@ias.u-psud.f jfrogel@aura-astronomy.org varoujan.gorjian@jpl.nasa.gov mwerner@sirtfweb.jpl.nasa.gov latter@ipac.caltech.edu smadden@cea.fr f.kemper@manchester.ac.uk msoey@umich.edu kolsen@ctio.noao.edu reach@ipac.caltech.edu vandyk@ipac.caltech.edu Lister.Staveley-Smith@csiro.au tueta@du.edu
B. A. Whitney et al 2008 The Astronomical Journal 136 18
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. The YSOs are biased toward intermediate- to high-mass and young evolutionary stages, because these overlap less with galaxies and evolved stars in color-magnitude space. The YSOs are highly correlated spatially with atomic and molecular gas, and are preferentially located in the shells and bubbles created by massive stars inside. They are more clustered than generic point sources, as expected if star formation occurs in filamentary clouds or shells. We applied a more stringent color-magnitude selection to produce a subset of "high-probability" YSO candidates. We fitted the spectral-energy distributions (SEDs) of this subset and derived physical properties for those that were well fitted. The total mass of these well-fitted YSOs is ~2900 M
and the total luminosity is ~2.1 × 106 L
. By extrapolating the mass function with a standard initial mass function and integrating, we calculate a current star-formation rate of ~0.06 M
yr–1, which is at the low end of estimates based on total ultraviolet and IR flux from the galaxy (~0.05 – 0.25 M
yr–1), consistent with the expectation that our current YSO list is incomplete. Follow-up spectroscopy and further data mining will better separate the different IR-bright populations and likely increase the estimated number of YSOs. The full YSO list is available as electronic tables, and the SEDs are available as an electronic figure for further use by the scientific community.
98.56.Si Magellanic Clouds and other irregular galaxies
95.80.+p Astronomical catalogs, atlases, sky surveys, databases, retrieval systems, archives, etc.
98.62.Qz Magnitudes and colors; luminosities
98.62.Ai Origin, formation, evolution, age, and star formation
Issue 1 (2008 July)
Received 2007 June 20 , accepted for publication 2008 April 1
Published 2008 May 27
B. A. Whitney et al 2008 The Astronomical Journal 136 18
D del-Castillo-Negrete et al 2004 Plasma Phys. Control. Fusion 46 A105
Oskar Painter et al 2001 J. Opt. A: Pure Appl. Opt. 3 S161