The methanol emission of isolated maser condensations: Statistical velocity distribution
| Autor: | I. E. Val'tts, G. M. Larionov |
|---|---|
| Rok vydání: | 2007 |
| Předmět: |
Physics
Molecular cloud Condensation Astronomy Astronomy and Astrophysics Astrophysics Large sample law.invention chemistry.chemical_compound chemistry Space and Planetary Science law Astrophysics::Solar and Stellar Astrophysics Astrophysics::Earth and Planetary Astrophysics Methanol Maser Astrophysics::Galaxy Astrophysics Line (formation) |
| Zdroj: | Astronomy Reports. 51:756-772 |
| ISSN: | 1562-6881 1063-7729 |
| Popis: | The distribution of the radial velocities of class I methanol masers relative to the velocities of their parent molecular clouds is analyzed. This analysis is based on catalog data for methanol masers detected up to the present time in both the northern and southern hemispheres, together with catalog data for the CS(2-1) line, which traces dense, quiescent gas. Results for a large sample of sources show that, in contrast to class II methanol masers, which undergo Keplerian motions in protoplanetary disks, class I methanol masers retain their velocities in the local system of rest of the surrounding medium, and do not participate in the ejection of matter in bipolar outflows. They can be adequately described using a model in which matter ejected from active parts of the associated star-forming regions flows around isolated maser condensations. This compresses the maser clumps, enhancing the concentration of methanol and facilitating collisional pumping of the masers. |
| Databáze: | OpenAIRE |
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