Are Globular Clusters the Remnant Nuclei of Progenitor Disk Galaxies?

TL;DR

This paper explores the hypothesis that globular clusters are the remnants of dwarf galaxy nuclei that merged to form larger galaxies, supported by their similar mass fractions and complex star formation histories.

Contribution

It proposes and discusses a scenario where globular clusters are surviving nuclei of dwarf galaxies, linking their properties to galaxy formation processes.

Findings

Globular clusters have a similar mass fraction to nuclear star clusters.

Massive globular clusters show complex star formation histories.

The scenario aligns with hierarchical galaxy formation models.

Abstract

The globular cluster system of a typical spheroidal galaxy makes up about 0.25% of the total galaxy mass (McLaughlin 1999). This is roughly the same mass fraction as contained in the nuclear star clus- ter (or stellar nucleus) present in most nearby low-mass galaxies. Motivated by this "coincidence", this Letter discusses a scenario in which globular clusters of present-day galaxies are the surviving nuclei of the dwarf galaxies that - according to the hierarchical merging paradigm of galaxy forma- tion - constitute the "building blocks" of present-day massive galaxies. This scenario, which was first suggested by Freeman (1993), has become more attractive recently in the light of studies that demonstrate a complex star formation history in a number of massive globular clusters.