Dynamical evolution of star clusters with top-heavy IMF

TL;DR

This study uses N-body simulations to explore how initial conditions like metallicity and density influence the evolution and survival of globular clusters with a top-heavy initial mass function over 12 billion years.

Contribution

It provides new insights into the dynamical evolution of star clusters with varying degrees of top-heaviness in their initial mass functions, considering early gas expulsion effects.

Findings

Dissolution time varies with IMF top-heaviness.

Minimum cluster mass for survival depends on initial conditions.

Clusters with more top-heavy IMFs dissolve faster.

Abstract

Several observational and theoretical studies suggest that the initial mass function (IMF) slope for massive stars in globular clusters (GCs) depends on the initial cloud density and metallicity, such that the IMF becomes increasingly top-heavy with decreasing metallicity and increasing the gas density of the forming object. Using N-body simulations of GCs starting with a top-heavy IMF and undergo early gas expulsion within a Milky Way-like potential, we show how such a cluster would evolve. By varying the degree of top-heaviness, we calculate the dissolution time and the minimum cluster mass needed for the cluster to survive after 12 Gyr of evolution.