THE LUMINOSITIES OF PROTOSTARS IN THE SPITZER c2d AND GOULD BELT LEGACY CLOUDS
- Department of Astronomy, Yale University, P.O. Box 208101, New Haven, CT 06520 (United States)
- National Optical Astronomy Observatories, Tucson, AZ (United States)
- Department of Astronomy, University of Texas at Austin, 2515 Speedway, Stop C1400, Austin, TX 78712-1205 (United States)
- Herzberg Institute, National Research Council of Canada, 5071 W. Saanich Road, Victoria, BC V9E 2E7 (Canada)
- Center for Interdisciplinary Exploration and Research in Astrophysics (CIERA), Department of Physics and Astronomy, 2145 Sheridan Road, Evanston, IL 60208 (United States)
- Institute for Astronomy, University of Hawaii at Manoa, Honolulu, HI 96822 (United States)
- Department of Astronomy, University of Massachusetts, Amherst, MA (United States)
- Astrophysics Group, Physics, University of Exeter, Exeter EX4 4QL (United Kingdom)
- Department of Astronomy, University of Maryland, College Park, MD 20742 (United States)
- School of Physics and Astronomy, Cardiff University, Queens Buildings, The Parade, Cardiff CF24 3AA (United Kingdom)
- Herschel Science Centre, ESAC-ESA, P.O. Box 78, E-28691 Villanueva de la Canada, Madrid (Spain)
- Space Science Institute, 4750 Walnut Street, Suite 205, Boulder, CO 80301 (United States)
- European Southern Observatory (ESO), Karl-Schwarzschild-Strasse 2, D-85748 Garching bei Muenchen (Germany)
Motivated by the long-standing 'luminosity problem' in low-mass star formation whereby protostars are underluminous compared to theoretical expectations, we identify 230 protostars in 18 molecular clouds observed by two Spitzer Space Telescope Legacy surveys of nearby star-forming regions. We compile complete spectral energy distributions, calculate L{sub bol} for each source, and study the protostellar luminosity distribution. This distribution extends over three orders of magnitude, from 0.01 L{sub Sun} to 69 L{sub Sun }, and has a mean and median of 4.3 L{sub Sun} and 1.3 L{sub Sun }, respectively. The distributions are very similar for Class 0 and Class I sources except for an excess of low luminosity (L{sub bol} {approx}< 0.5 L{sub Sun }) Class I sources compared to Class 0. 100 out of the 230 protostars (43%) lack any available data in the far-infrared and submillimeter (70 {mu}m <{lambda} < 850 {mu}m) and have L{sub bol} underestimated by factors of 2.5 on average, and up to factors of 8-10 in extreme cases. Correcting these underestimates for each source individually once additional data becomes available will likely increase both the mean and median of the sample by 35%-40%. We discuss and compare our results to several recent theoretical studies of protostellar luminosities and show that our new results do not invalidate the conclusions of any of these studies. As these studies demonstrate that there is more than one plausible accretion scenario that can match observations, future attention is clearly needed. The better statistics provided by our increased data set should aid such future work.
- OSTI ID:
- 22130811
- Journal Information:
- Astronomical Journal (New York, N.Y. Online), Vol. 145, Issue 4; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 1538-3881
- Country of Publication:
- United States
- Language:
- English
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