A CANDIDATE DETECTION OF THE FIRST HYDROSTATIC CORE
- Department of Astronomy, University of California at Berkeley, 601 Campbell Hall, Berkeley, CA 94720 (United States)
- Department of Astronomy and Space Science, Astrophysical Research Center for the Structure and Evolution of the Cosmos, Sejong University, Seoul 143-747 (Korea, Republic of)
- Department of Astronomy, University of Texas at Austin, 1 University Station, C1400, Austin, TX 78712 (United States)
- National Research Council Canada, Herzberg Institute of Astrophysics, 5071 West Saanich Road, Victoria BC V9E 2E7 (Canada)
The first hydrostatic core (FHSC) represents a very early phase in the low-mass star formation process, after collapse of the parent core has begun but before a true protostar has formed. This large (few AU), cool (100 K), pressure-supported core of molecular hydrogen is expected from theory, but has yet to be observationally verified. Here, we present observations of an excellent candidate for the FHSC phase: Per-Bolo 58, a dense core in Perseus that was previously believed to be starless. The 70 {mu}m flux of 65 mJy, from new deep Spitzer MIPS observations, is consistent with that expected for the FHSC. A low signal-to-noise detection at 24 {mu}m leaves open the possibility that Per-Bolo 58 could be a very low luminosity protostar, however. We utilize radiative transfer models to determine the best-fitting FHSC and protostar models to the spectral energy distribution and 2.9 mm visibilities of Per-Bolo 58. The source is consistent with an FHSC with some source of lower opacity through the envelope allowing 24 {mu}m emission to escape; a small outflow cavity and a cavity in the envelope are both possible. While we are unable to rule out the presence of a protostar, if present it would be one of the lowest luminosity protostellar objects yet observed, with an internal luminosity of {approx}0.01 L {sub sun}.
- OSTI ID:
- 21452771
- Journal Information:
- Astrophysical Journal Letters, Vol. 722, Issue 1; Other Information: DOI: 10.1088/2041-8205/722/1/L33; ISSN 2041-8205
- Country of Publication:
- United States
- Language:
- English
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