Star Formation Relations in Nearby Molecular Clouds
| Autor: | Amanda Heiderman, Neal J. Evans, Nalin Vutisalchavakul |
|---|---|
| Rok vydání: | 2014 |
| Předmět: |
Physics
010308 nuclear & particles physics Star formation Molecular cloud FOS: Physical sciences Astronomy and Astrophysics Plasma Astrophysics Astrophysics - Astrophysics of Galaxies 01 natural sciences Volume (thermodynamics) 13. Climate action Space and Planetary Science Astrophysics of Galaxies (astro-ph.GA) 0103 physical sciences Linear relation 10. No inequality Dispersion (water waves) 010303 astronomy & astrophysics Astrophysics::Galaxy Astrophysics |
| DOI: | 10.48550/arxiv.1401.3287 |
| Popis: | We test some ideas for star formation relations against data on local molecular clouds. On a cloud by cloud basis, the relation between the surface density of star formation rate and surface density of gas divided by a free-fall time, calculated from the mean cloud density, shows no significant correlation. If a crossing time is substituted for the free-fall time, there is even less correlation. Within a cloud, the star formation rate volume and surface densities increase rapidly with the corresponding gas densities, faster than predicted by models using the free-fall time defined from the local density. A model in which the star formation rate depends linearly on the mass of gas above a visual extinction of 8 mag describes the data on these clouds, with very low dispersion. The data on regions of very massive star formation, with improved star formation rates based on free-free emission from ionized gas, also agree with this linear relation. Comment: 15 pages, 8 figures, in press in ApJ |
| Databáze: | OpenAIRE |
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