Star Formation Relations in Nearby Molecular Clouds
| Autor: | Evans II, Neal J., Heiderman, Amanda, Vutisalchavakul, Nalin |
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| Rok vydání: | 2014 |
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| Druh dokumentu: | Working Paper |
| DOI: | 10.1088/0004-637X/782/2/114 |
| 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: | arXiv |
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