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Title: On the nature of the deeply embedded protostar OMC-2 FIR 4

We use mid-infrared to submillimeter data from the Spitzer, Herschel, and Atacama Pathfinder Experiment telescopes to study the bright submillimeter source OMC-2 FIR 4. We find a point source at 8, 24, and 70 μm, and a compact, but extended source at 160, 350, and 870 μm. The peak of the emission from 8 to 70 μm, attributed to the protostar associated with FIR 4, is displaced relative to the peak of the extended emission; the latter represents the large molecular core the protostar is embedded within. We determine that the protostar has a bolometric luminosity of 37 L {sub ☉}, although including more extended emission surrounding the point source raises this value to 86 L {sub ☉}. Radiative transfer models of the protostellar system fit the observed spectral energy distribution well and yield a total luminosity of most likely less than 100 L {sub ☉}. Our models suggest that the bolometric luminosity of the protostar could be as low as 12-14 L {sub ☉}, while the luminosity of the colder (∼20 K) extended core could be around 100 L {sub ☉}, with a mass of about 27 M {sub ☉}. Our derived luminosities for the protostar OMC-2 FIR 4more » are in direct contradiction with previous claims of a total luminosity of 1000 L {sub ☉}. Furthermore, we find evidence from far-infrared molecular spectra and 3.6 cm emission that FIR 4 drives an outflow. The final stellar mass the protostar will ultimately achieve is uncertain due to its association with the large reservoir of mass found in the cold core.« less
Authors:
 [1] ; ;  [2] ;  [3] ;  [4] ;  [5] ;  [6] ;  [7] ;  [8] ;  [9]
  1. National Optical Astronomy Observatory, 950 N. Cherry Avenue, Tucson, AZ 85719 (United States)
  2. Ritter Astrophysical Observatory, Department of Physics and Astronomy, University of Toledo, 2801 W. Bancroft Street, Toledo, OH 43606 (United States)
  3. Instituto de Astrofísica de Andalucía, CSIC, Camino Bajo de Huétor 50, E-18008 Granada (Spain)
  4. Max-Planck-Institut für Astronomie, Königstuhl 17, D-69117 Heidelberg (Germany)
  5. NHSC/IPAC, California Institute of Technology, 770 S. Wilson Ave., Pasadena, CA 91125 (United States)
  6. ESO, Karl-Schwarzschild-Strasse 2, D-85748, Garching bei München (Germany)
  7. Department of Astronomy and Astrophysics, Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai 400005 (India)
  8. USRA-SOFIA, DAOF, 2825 E. Ave. P, Palmdale, CA 93550 (United States)
  9. National Radio Astronomy Observatory, Charlotttesville, VA 22903 (United States)
Publication Date:
OSTI Identifier:
22357020
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 786; Journal Issue: 1; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; BOLOMETERS; EMISSION; ENERGY SPECTRA; INTERMEDIATE INFRARED RADIATION; LUMINOSITY; MASS; POINT SOURCES; PROTOSTARS; RADIANT HEAT TRANSFER; STARS; TELESCOPES