The maximum stellar mass, star-cluster formation and composite stellar populations

By C. Weidner, Pavel Kroupa. 2005

272 citations recorded by the source corpus.

We demonstrate that the mass of the most massive star in a cluster correlates non-trivially with the cluster mass. A simple algorithm, according to which a cluster is filled up with stars that are chosen randomly from the standard initial mass function (IMF) but sorted with increasing mass, yields an excellent description of the observational data. Algorithms based on random sampling from the IMF without sorted adding are ruled out with a confidence larger than 0.9999. A physical explanation of this would be that a cluster forms by more-massive stars being consecutively added until the resulting feedback energy suffices to revert cloud contraction and stops further star formation. This has important implications for composite populations. For example, 10 4 clusters of mass 10 2 M ⊙ will not produce the same IMF as one cluster with a mass of 10 6 M ⊙ . It also supports the notion that the integrated galaxial stellar IMF (IGIMF) should be steeper than the stellar IMF and that it should vary with the star formation rate of a galaxy.

Subfields: Astronomy and Astrophysics, Instrumentation, Statistical and Nonlinear Physics

View Paper: https://www.semanticscholar.org/paper/48e3bb7e7c9ffdf9d6a853d9abf4635ec42464c9

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Citations in the corpus

A GALEX ULTRAVIOLET IMAGING SURVEY OF GALAXIES IN THE LOCAL VOLUME (2010, background): “Briefly, in the “integrated galactic stellar initial mass function” (IGIMF; Kroupa & Weidner 2003; Weidner & Kroupa 2005, 2006), it is assumed that: (i) all stars form in clusters; (ii) the maximum mass of a star formed in a cluster is a deterministic function of the cluster mass, and this maximum…”
Physical Processes in the Interstellar Medium (2014, background): “The upper mass limit in more massive clusters seems to be higher than in lower-mass clusters, an effect that goes beyond the statistical fluctuations expected for purely random sampling from a universal distribution (see e.g. Weidner & Kroupa, 2004, 2006; Weidner et al., 2010).”
Galaxy and Mass Assembly (GAMA): the star formation rate dependence of the stellar initial mass function (2011, methodology): “Whether the IGIMF is universal (Elmegreen 2006) or differs from the star cluster IMF (Weidner & Kroupa 2005, 2006) is again a much debated subject.”
The stellar and sub-stellar IMF of simple and composite populations (2011, methodology): “1 in Weidner & Kroupa 2005, as derived by Weidner et al. 2004 using observed maximum star cluster masses).”
On the Normalization of the Cosmic Star Formation History (2006, background): “A modified Salpeter form with a turnover below1M⊙, though, is still a reasonable model (e.g., Baldry & Glazebrook 2003), and other currently favoured IMFs include those of Kroupa (2001), Baldry & Glazebrook (2003), and Weidner & Kroupa (2005, 2006).”