A MASSIVE PROTOSTAR FORMING BY ORDERED COLLAPSE OF A DENSE, MASSIVE CORE

Journal Article · Wed Apr 10 04:00:00 EDT 2013 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/767/1/58· OSTI ID:22167408

Zhang, Yichen; Tan, Jonathan C.; Telesco, Charles ^[1]; De Buizer, James M.; Sandell, Goeran; Shuping, Ralph ^[2]; Beltran, Maria T. ^[3]; Churchwell, Ed; Whitney, Barbara ^[4]; McKee, Christopher F. ^[5]

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1. Department of Astronomy, University of Florida, Gainesville, FL 32611 (United States)
2. SOFIA-USRA, NASA Ames Research Center, MS 232-12, Building N232, P.O. Box 1, Moffett Field, CA 94035 (United States)
3. INAF-Osservatorio Astrofisico di Arcetri, Largo E. Fermi 5, Firenze I-50125 (Italy)
4. Department of Astronomy, University of Wisconsin, Madison, WI 53706 (United States)
5. Department of Astronomy and Astrophysics, University of California, Berkeley, CA 94720 (United States)

We present 30 and 40 {mu}m imaging of the massive protostar G35.20-0.74 with SOFIA-FORCAST. The high surface density of the natal core around the protostar leads to high extinction, even at these relatively long wavelengths, causing the observed flux to be dominated by that emerging from the near-facing outflow cavity. However, emission from the far-facing cavity is still clearly detected. We combine these results with fluxes from the near-infrared to mm to construct a spectral energy distribution (SED). For isotropic emission the bolometric luminosity would be 3.3 Multiplication-Sign 10{sup 4} L{sub Sun }. We perform radiative transfer modeling of a protostar forming by ordered, symmetric collapse from a massive core bounded by a clump with high-mass surface density, {Sigma}{sub cl}. To fit the SED requires protostellar masses {approx}20-34 M{sub Sun} depending on the outflow cavity opening angle (35 Degree-Sign -50 Degree-Sign ), and {Sigma}{sub cl} {approx} 0.4-1 g cm{sup -2}. After accounting for the foreground extinction and the flashlight effect, the true bolometric luminosity is {approx}(0.7-2.2) Multiplication-Sign 10{sup 5} L{sub Sun }. One of these models also has excellent agreement with the observed intensity profiles along the outflow axis at 10, 18, 31, and 37 {mu}m. Overall our results support a model of massive star formation involving the relatively ordered, symmetric collapse of a massive, dense core and the launching bipolar outflows that clear low-density cavities. Thus a unified model may apply for the formation of both low- and high-mass stars.

• OSTI ID: 22167408
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 1 Vol. 767; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
BOLOMETERS
CAVITIES
EMISSION
ENERGY SPECTRA
LUMINOSITY
PROTOSTARS
RADIANT HEAT TRANSFER
SIMULATION
STARS
SYMMETRY
UNIFIED MODEL
WAVELENGTHS