Dark Matter in Globular Clusters

TL;DR

This paper reviews the potential presence of dark matter in globular clusters, analyzing observational data and models to suggest that a significant portion of their mass remains unobserved, possibly as low-mass stars or white dwarfs.

Contribution

It provides a comprehensive review of methods and evidence regarding dark matter in globular clusters, highlighting the possibility of substantial unseen mass.

Findings

Approximately half of the mass in studied clusters is unobserved.

Unobserved mass may consist of low-mass stars and white dwarfs.

Dark matter presence is consistent with cluster dynamics and structure.

Abstract

We first review reasons why dark matter is an interesting issue in connection with star clusters. Next we consider to what extent the presence of dark matter is consistent with their dynamics and structure. We review various model-dependent and model-independent methods which have been applied to two well studied clusters, NGC 6397 and 47 Tuc. We suggest that about half of the mass in each object is still unobserved, possibly in the form of a mixture of low-mass stars and white dwarfs.