Feedback from Massive Stars and Gas Expulsion from Proto-Globular Clusters
Journal
Date Issued
2015
Author(s)
Description
An anonymous referee is acknowledged for useful comments. We wish to thank C. Nipoti, P. Londrillo, and F. Brighenti for several interesting discussions. Simulations were carried on at the CINECA center (Bologna, Italy) with CPU time assigned under ISCRA grants. F.C. and D.R. acknowledge Financial support from PRIN MIUR 2010-2011, project The Chemical and Dynamical Evolution of the Milky Way and Local Group Galaxies, prot. 2010LY5N2T and from INAF under the contract PRIN-INAF-2012. C.G.F. acknowledges funding from the European Research Council for the FP7 ERC starting grant project LOCALSTAR. A.D.E. acknowledges support from PRIN INAF 2014.
Abstract
Globular clusters (GCs) are considerably more complex structures than previously thought, harboring at least two stellar generations that present clearly distinct chemical abundances. Scenarios explaining the abundance patterns in GCs mostly assume that originally the clusters had to be much more massive than today, and that the second generation of stars originates from the gas shed by stars of the first generation (FG). The lack of metallicity spread in most GCs further requires that the supernova-enriched gas ejected by the FG is completely lost within ̃30 Myr, a hypothesis never tested by means of three-dimensional hydrodynamic simulations. In this paper, we use 3D hydrodynamic simulations including stellar feedback from winds and supernovae, radiative cooling and self-gravity to study whether a realistic distribution of OB associations in a massive proto-GC of initial mass Mtot ̃ 107 M☉ is sufficient to expel its entire gas content. Our numerical experiment shows that the coherence of different associations plays a fundamental role: as the bubbles interact, distort, and merge, they carve narrow tunnels that reach deeper and deeper toward the innermost cluster regions, and through which the gas is able to escape. Our results indicate that after 3 Myr, the feedback from stellar winds is responsible for the removal of ̃40% of the pristine gas, and that after 14 Myr, 99% of the initial gas mass has been removed.
Volume
814
Issue
1
Start page
L14
Issn Identifier
0004-637X
Ads BibCode
2015ApJ...814L..14C
Rights
open.access
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