On the nature of the deeply embedded protostar OMC-2 FIR 4
- National Optical Astronomy Observatory, 950 N. Cherry Avenue, Tucson, AZ 85719 (United States)
- Ritter Astrophysical Observatory, Department of Physics and Astronomy, University of Toledo, 2801 W. Bancroft Street, Toledo, OH 43606 (United States)
- Instituto de Astrofísica de Andalucía, CSIC, Camino Bajo de Huétor 50, E-18008 Granada (Spain)
- Max-Planck-Institut für Astronomie, Königstuhl 17, D-69117 Heidelberg (Germany)
- NHSC/IPAC, California Institute of Technology, 770 S. Wilson Ave., Pasadena, CA 91125 (United States)
- ESO, Karl-Schwarzschild-Strasse 2, D-85748, Garching bei München (Germany)
- Department of Astronomy and Astrophysics, Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai 400005 (India)
- USRA-SOFIA, DAOF, 2825 E. Ave. P, Palmdale, CA 93550 (United States)
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 4 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.
- OSTI ID:
- 22357020
- Journal Information:
- Astrophysical Journal, Vol. 786, Issue 1; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
- Country of Publication:
- United States
- Language:
- English
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