A SEARCH FOR VERY LOW-LUMINOSITY OBJECTS IN GOULD BELT CLOUDS

• Published in: The Astrophysical journal. Supplement series Vol. 225; no. 2; p. 26
• Main Authors: Kim, Mi-Ryang, Lee, Chang Won, Dunham, Michael M., Evans II, Neal J., Kim, Gwanjeong, Allen, Lori E.
• Format: Journal Article
• Language: English
• Published: United States The American Astronomical Society 01.08.2016
• Subjects: Accretion; ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; Belts; BOLOMETERS; Clouds; EMISSION; Forming; INFRARED SURVEYS; infrared: ISM; INTERSTELLAR SPACE; LUMINOSITY; MASS; MOLECULAR IONS; Pollution sources; Searching; STARS; stars: formation
• ISSN: 0067-0049; 1538-4365
• DOI: 10.3847/0067-0049/225/2/26

ABSTRACT We present the results of a search for Very Low-Luminosity Objects (VeLLOs) in the Gould Belt (GB) clouds using infrared and sub-millimeter (sub-mm) data from 1.25 to 850 m and our (J = 1−0) observations. We modified the criteria by Dunham et al. to select the VeLLOs in the GB clouds, finding 95 VeLLO candidates, 79 of which are newly identified in this study. Out of 95 sources, 44 were detected in both sub-mm continuum and emission and were classified as Group A (the VeLLOs), and 51 sources detected in either sub-mm emission or emission were classified with Group B as candidate VeLLOs. We find that these VeLLOs and the candidates are forming in environments different from those of the likely VeLLOs. Seventy-eight sources are embedded within their molecular clouds, and thus are likely VeLLOs forming in a dense environment. The remaining 17 sources are located in low-level extinction regions ( ) connected to the clouds, and can be either background sources or candidate substellar objects forming in an isolated mode. The VeLLOs and the candidates are likely more luminous and their envelopes tend to be more massive in denser environments. The VeLLOs and the candidates are more populous in the clouds where more YSOs form, indicating that they form in a manner similar to that of normal YSOs. The bolometric luminosities and temperatures of the VeLLOs are compared to predictions of episodic accretion models, showing that the low luminosities for most VeLLOs can be well explained by their status in the quiescent phases of a cycle of episodic mass accretion.