The initial mass function in clusters: theoretical and observational perspectives.

We review the success of current simulations in reproducing the observed initial mass function (IMF) in clusters and show that whereas the two main types of simulation invoke the same physics to explain the point at which the IMF flattens from a Salpeter slope, they reproduce the Salpeter tail itself by quite different means. We highlight the fact that a proper modelling of the thermal properties of star-forming gas is probably crucial in explaining why the IMF is apparently quite insensitive to cloud parameters. We also explore how the mass of a cluster’s most massive star depends on cluster mass and how this issue impacts the relationship between the IMF in individual clusters and the integrated galactic IMF. We emphasise the importance of a careful statistical treatment of data in this area. [ABSTRACT FROM AUTHOR]