The mass function of young star clusters in the Antennae

Abstract

The Antennae is a pair of late type spirals in the course of merging. The interaction triggered an ongoing strong burst of star formation that also produced a large number of Young Star Clusters (YSCs), many of which seem to be young Globular Clusters (GCs). The observed Luminosity Function of the YSC system is a power-law. We use evolutionary synthesis models for star clusters in comparison with HST WFPC observations of the YSC system in the Antennae to analyse the mass function of this ∼ 2 × 108 yr young star cluster system. Properly accounting for age spread effects by individually age-dating the YSCs we find that the intrinsic Mass Function (MF) is log-normal in shape and in intriguing agreement with the MF of old GC systems. We discuss this MF in the context of cluster formation and dynamical effects in the tidal field of the parent galaxy and speculate about its future evolution.