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The Herschel view of the on-going star formation in the Vela-C molecular cloud
- Source :
- Astronomy and Astrophysics-A&A, Astronomy and Astrophysics-A&A, 2012, 539, pp.A156. ⟨10.1051/0004-6361/201117811⟩, Astronomy and Astrophysics-A&A, EDP Sciences, 2012, 539, pp.A156
- Publication Year :
- 2012
-
Abstract
- As part of the Herschel guaranteed time key program 'HOBYS', we present the photometric survey of the star forming region Vela-C, one of the nearest sites of low-to-high-mass star formation in the Galactic plane. Vela-C has been observed with PACS and SPIRE in parallel mode between 70 um and 500 um over an area of about 3 square degrees. A photometric catalogue has been extracted from the detections in each band, using a threshold of 5 sigma over the local background. Out of this catalogue we have selected a robust sub-sample of 268 sources, of which 75% are cloud clumps and 25% are cores. Their Spectral Energy Distributions (SEDs) have been fitted with a modified black body function. We classify 48 sources as protostellar and 218 as starless. For two further sources, we do not provide a secure classification, but suggest they are Class 0 protostars. From SED fitting we have derived key physical parameters. Protostellar sources are in general warmer and more compact than starless sources. Both these evidences can be ascribed to the presence of an internal source(s) of moderate heating, which also causes a temperature gradient and hence a more peaked intensity distribution. Moreover, the reduced dimensions of protostellar sources may indicate that they will not fragment further. A virial analysis of the starless sources gives an upper limit of 90% for the sources gravitationally bound and therefore prestellar. We fit a power law N(logM) prop M^-1.1 to the linear portion of the mass distribution of prestellar sources. This is in between that typical of CO clumps and those of cores in nearby star-forming regions. We interpret this as a result of the inhomogeneity of our sample, which is composed of comparable fractions of clumps and cores.<br />9 pages, 7 figures, accepted by A&A
- Subjects :
- individual objects
stars
FOS: Physical sciences
Astrophysics
clouds
Astrophysics::Cosmology and Extragalactic Astrophysics
Vela
01 natural sciences
Power law
circumstellar matter
Virial theorem
0103 physical sciences
Protostar
Astrophysics::Solar and Stellar Astrophysics
submillimeter
Vela-C
010303 astronomy & astrophysics
Solar and Stellar Astrophysics (astro-ph.SR)
Astrophysics::Galaxy Astrophysics
QB
Physics
Mass distribution
010308 nuclear & particles physics
Star formation
[SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR]
Molecular cloud
formation
Astronomy and Astrophysics
Galactic plane
[PHYS.ASTR.SR]Physics [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR]
Astrophysics - Solar and Stellar Astrophysics
Space and Planetary Science
Subjects
Details
- Language :
- English
- ISSN :
- 00046361 and 14320746
- Database :
- OpenAIRE
- Journal :
- Astronomy and Astrophysics-A&A, Astronomy and Astrophysics-A&A, 2012, 539, pp.A156. ⟨10.1051/0004-6361/201117811⟩, Astronomy and Astrophysics-A&A, EDP Sciences, 2012, 539, pp.A156
- Accession number :
- edsair.doi.dedup.....bbca2ccd2b4a807c7cf2e7e84cb78165