Dust emission from star-forming regions. IV. Dense cores in the Orion B molecular cloud.
Abstract
In a search for isothermal pre-stellar cores and protostars we surveyed with SEST and IRAM MRT part of the Orion B GMC for its λ1.3mm dust emission. We used the CS(2-1) survey by Lada et al. (1991a; LBS) as a search list. We determine the morphology of the detected cloud cores with angular resolutions of 23" (SEST) and 12", respectively. About one half of these cores have a compact core surrounded by an extended envelope. The λ1.3mm dust emission maps were compared with NIR (2.13 μm) and FIR (IRAS) maps to discriminate between isothermal and self-luminous cores. About one half of the cores were classified as isothermal. A comparison of virial masses derived from CS line widths with gas masses derived from λ1.3mm dust emission shows that virial masses are on average by a factor of 20...30 larger. This can be explained by line opacity and by the larger beamwidths (1.8' vs. 23" and 12", respectively) of the CS survey.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- August 1996
- Bibcode:
- 1996A&A...312..569L
- Keywords:
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- INTERSTELLAR MEDIUM;
- DUST;
- CLOUDS: INDIVIDUAL (LYNDS 1630);
- STARS: FORMATION OF