The Globular Cluster Mass Function as a Remnant of Violent Birth

TL;DR

This paper proposes that the log-normal mass distribution of metal-poor globular clusters results from early rapid evolution of an initial power-law distribution in dense high-redshift galaxy environments, influenced by various dynamical processes.

Contribution

It introduces a model linking early cluster formation and evolution to the observed globular cluster mass function, emphasizing the impact of high-redshift galaxy conditions.

Findings

Monte Carlo models show early formation of a log-normal mass function.

Dynamical processes like evaporation and collisions shape the cluster mass distribution.

Clusters formed during galaxy mergers contribute to metal-rich populations.

Abstract

The log-normal shape of the mass function for metal-poor halo globular clusters is proposed to result from an initial M^{-2} power law modified rapidly by evaporation, collisions with clouds, and mutual cluster interactions in the dense environment of a redshift z~5-15 disk galaxy. Galaxy interactions subsequently spray these clusters into the galaxy group environment, where they fall into other growing galaxies and populate their halos. Clusters forming later in z~2-5 galaxies, and those formed during major mergers, produce metal-rich globulars. Monte Carlo models of evolving cluster populations demonstrate the early formation of a log-normal mass function for typical conditions in high-redshift galaxies.