Inverting the dynamical evolution of globular clusters: clues to their origin
| Autor: | Gieles, Mark, Alexander, Poul |
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| Rok vydání: | 2015 |
| Předmět: | |
| Druh dokumentu: | Working Paper |
| Popis: | Scaling relations for globular clusters (GC) differ from scaling relations for pressure supported (elliptical) galaxies. We show that two-body relaxation is the dominant mechanism in shaping the bivariate dependence of density on mass and Galactocentric distance for Milky Way GCs with masses <10^6 Msun, and it is possible, but not required, that GCs formed with similar scaling relations as ultra-compact dwarf galaxies. We use a fast cluster evolution model to fit a parameterised model for the initial properties of Milky Way GCs to the observed present-day properties. The best-fit cluster initial mass function is substantially flatter (power-law index alpha =- 0.6+/-0.2) than what is observed for young massive clusters (YMCs) forming in the nearby Universe (alpha =~-2). A slightly steeper CIMF is allowed when considering the metal-rich GCs separately (alpha =~-1.2+/-0.4$). If stellar mass loss and two-body relaxation in the Milky Way tidal field are the dominant disruption mechanisms, then GCs formed differently from YMCs. Comment: 8 pages, 5 figures, invited review for IAUS 316, "Formation, evolution, and survival of massive star clusters", eds. C. Charbonnel & A. Nota |
| Databáze: | arXiv |
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