Clumpy filaments of the Chamaeleon I cloud: C$\mathsf{^{18}}$O mapping with the SEST
| Autor: | Lauri K. Haikala, M. Toriseva, Jorma Harju, Kalevi Mattila |
|---|---|
| Rok vydání: | 2005 |
| Předmět: |
Physics
010308 nuclear & particles physics Turbulence Astronomy and Astrophysics Astrophysics::Cosmology and Extragalactic Astrophysics Astrophysics 01 natural sciences law.invention Telescope Stars Space and Planetary Science law 0103 physical sciences Mass spectrum Astrophysics::Solar and Stellar Astrophysics Chamaeleon 010303 astronomy & astrophysics Astrophysics::Galaxy Astrophysics |
| Zdroj: | Astronomy & Astrophysics. 431:149-163 |
| ISSN: | 1432-0746 0004-6361 |
| Popis: | The Chamaeleon I dark cloud (Cha I} has been mapped in C18O J=1-0 with an angular resolution of 1 arcmin using the SEST telescope. The large scale structures previously observed with lower spatial resolution in the cloud turn into a network of clumpy filaments. The automatic Clumpfind routine developed by Williams et al. 1994 is used to identify individual clumps in a consistent way. Altogether 71 clumps were found and the total mass of these clumps is 230 Mo. The dense 'cores' detected with the NANTEN telescope (Mizuno et al. 1999) and the very cold cores detected in the ISOPHOT serendipity survey (Toth et al. 2000) form parts of these filaments but decompose into numerous 'clumps' The filaments are preferentially oriented at right angles to the large-scale magnetic field in the region. We discuss the cloud structure, the physical characteristics of the clumps and the distribution of young stars. The observed clump mass spectrum is compared with the predictions of the turbulent fragmentation model of Padoan & Nordlund 2002. An agreement is found if fragmentation has been driven by very large-scale hypersonic turbulence, and if it has had time to dissipate into modestly supersonic turbulence in the interclump gas by the present time. |
| Databáze: | OpenAIRE |
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