Open AccessThe maximum stellar mass, star‐cluster formation and composite stellar populations
Author(s) -
Weidner Carsten,
Kroupa Pavel
Publication year - 2006
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1111/j.1365-2966.2005.09824.x
Subject(s) - physics , astrophysics , initial mass function , star cluster , star formation , cluster (spacecraft) , mass segregation , stars , stellar mass , galaxy cluster , galaxy , astronomy , star (game theory) , computer science , programming language
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.