Gas expulsion and the destruction of massive young clusters

By Simon Bastian. 2006

288 citations recorded by the source corpus.

We examine the luminosity and dynamical mass estimates for young massive stellar clusters. For many young (<50 Myr) clusters, the luminosity and dynamical mass estimates differ by a significant amount. We explain this as being due to many young clusters being out of virial equilibrium (which is assumed in dynamical mass estimates) because the clusters are undergoing violent relaxation after expelling gas not used in star formation. We show that, if we assume that luminous mass estimates are correct (for a standard initial mass function), at least 50 per cent of young clusters for which dynamical masses are known are likely to be destroyed within a few tens of Myr of their formation. Even clusters which will retain a bound core may lose a large fraction of their stellar mass. We also show that the core radius and other structural parameters change significantly during the violent relaxation that follows gas expulsion and that they should be considered instantaneous values only, not necessarily reflecting the final state of the cluster. In particular we note that the increasing core radii observed in young LMC/SMC clusters can be well explained as an effect of rapid gas loss.

Subfields: Astronomy and Astrophysics

View Paper: https://www.semanticscholar.org/paper/43cb689c40a4cafdffdbef25be2a951855b03cd0

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Citations in the corpus

The dynamical state of stellar structure in star‐forming regions (2011, background): “In previous studies, the SFE has been identified as a key parameter which determines the survival chances of stellar clusters upon gas expulsion (e.g. Goodwin & Bastian 2006).”
Young Massive Star Clusters (2010, background): “4 appear to have dynamical masses too high for their luminosities, and the intuitive explanation is that these clusters are expanding and are possibly even unbound (Goodwin & Bastian 2006).”
A double main-sequence turn-off in the rich star cluster NGC 1846 in the Large Magellanic Cloud (2007, background): “…of massive stellar winds and supernova explosions expel any remaining gas from a very young star cluster within only a few Myr (e.g., Bastian & Goodwin 2006), leading to strong changes in the cluster’s internal dynamics and structure (see e.g., Goodwin & Bastian 2006, and references therein).”
The stellar and sub-stellar IMF of simple and composite populations (2011, background): “…segregation which leads to a dynamically decoupled central core of OB stars is an important mechanism for reducing the measured mass-to-light ratio (Boily et al. 2005), while rapid expulsion of residual gas from forming clusters enhances the measured mass-tolight ratios (Goodwin & Bastian 2006).”
The Dramatic Size Evolution of Elliptical Galaxies and the Quasar Feedback (2008, background): “The puffing up of a system by rapid mass loss is a well known phenomenon, extensively studied both analytically and through numerical simulations, with reference to galaxies (Biermann & Shapiro 1979), and, especially, to globular clusters (Hills 1980; Goodwin & Bastian 2006).”
On the fraction of star formation occurring in bound stellar clusters (2012, background): “…2012 The Author Monthly Notices of the Royal Astronomical Society C© 2012 RAS Downloaded from https://academic.oup.com/mnras/article-abstract/426/4/3008/1014654 by guest on 28 July 2018 Kroupa 2003a,b; Bastian & Goodwin 2006; Goodwin & Bastian 2006; Baumgardt & Kroupa 2007; Parmentier et al. 2008).”
The formation of very wide binaries during the star cluster dissolution phase (2010, background): “The latter value forQ is expected for young clusters with an eff ctive star forming efficiency of 33% (Goodwin & Bastian 2006).”
DYNAMICAL MASS SEGREGATION ON A VERY SHORT TIMESCALE (2009, background): “In particular, young clusters seem to expand significantly in the first few Myr (Bastian et al. 2008), possibly due to the effects of multiple stellar encounters (van den Berk et al. 2007) or by the rapid expulsion of primordial gas (Goodwin & Bastian 2006).”
The relation between the most-massive star and its parental star cluster mass (2009, background): “…the star clusters should still be embedded in their natal gas cloud or at least be very young, such that gas expulsion would not have effected them strongly (Lada et al. 1984; Goodwin 1997; Kroupa et al. 2001; Goodwin & Bastian 2006; Weidner et al. 2007; Pellerin et al. 2006; Bastian & Goodwin”
On the star formation rate – brightest cluster relation: estimating the peak star formation rate in post-merger galaxies (2008, background): “Note that we have neither included the effects of infant-weight loss (Goodwin & Bastian 2006) nor included cluster mass loss due to tidal effects (e.g. Lamers et al. 2005; Gieles et al. 2006c), both of which would make older clusters less massive (on average) and hence decrease their luminosity…”
A Universal Stellar Initial Mass Function? A critical look at variations in extreme environments (2010, background): “Stars will diffuse out from their natal unbound associations into the field over some timescale that depends on their initial velocity dispersion (e.g. Goodwin & Bastian 2006), but is thought to be on the order of several Myr.”
Massive stars in massive clusters II: Disruption of bound clusters by photoionization (2012, background): “Hills (1980) and later Goodwin (1997), Boily & Kroupa (2003b), Boily & Kroupa (2003a) and Goodwin & Bastian (2006) studied the effects of removing residual gas from embedded clusters at various rates.”
Kinematics in Young Star Clusters and Associations with Gaia DR2 (2018, background): “Much attention has been focused on the role of gas expulsion, which will cause a cluster to expand and can cause bound embedded clusters to become unbound (Mathieu 1983; Elmegreen 1983; Adams 2000; Kroupa et al. 2001; Goodwin & Bastian 2006; Pelupessy & Portegies Zwart 2012; Brinkmann et al. 2017).”
The mass function of young star clusters in spiral galaxies (2008, background): “During the ensuing violent relaxation, clusters may disrupt completely or partially and undergo a phase of “infant mortality” or “infant weight loss” which lasts up to a few tens of Myr (Kroupa & Boily 2002; Lada & Lada 2003; Goodwin & Bastian 2006; Whitmore et al. 2007).”