The PIPER Survey. II. The Globular Cluster Systems of Low Surface Brightness Galaxies in the Perseus Cluster

TL;DR

This study uses Hubble imaging to analyze the globular cluster systems of 50 low surface brightness galaxies in the Perseus cluster, revealing diverse properties and potential insights into galaxy formation.

Contribution

First detailed analysis of globular clusters in LSB galaxies within the Perseus cluster, including structural properties and implications for galaxy formation scenarios.

Findings

Approximately half are ultra-diffuse galaxies (UDGs).

Some galaxies host rich globular cluster systems comparable to those in the Coma cluster.

GC sizes extend beyond host galaxy sizes, and GC colors match host stars, suggesting co-formation or disrupted GCs.

Abstract

We present Hubble Space Telescope ACS/WFC and WFC3/UVIS imaging for a sample of 50 low surface brightness (LSB) galaxies in the $\sim$10$^{15}$ M$_{\odot}$ Perseus cluster, which were originally identified in ground-based imaging. We measure the structural properties of these galaxies and estimate the total number of globular clusters (GCs) they host. Around half of our sample galaxies meet the strict definition of an ultra-diffuse galaxy (UDG), while the others are UDG-like but are either somewhat more compact or slightly brighter. A small number of galaxies reveal systems with many tens of GCs, rivalling some of the richest GC systems known around UDGs in the Coma cluster. We find the sizes of rich GC systems, in terms of their half-number radii, extending to $\sim$1.2 times the half-light radii of their host galaxy on average. The mean colours of the GC systems are the same, within the uncertainties, as those of their host galaxy stars. This suggests that GCs and galaxy field stars may have formed at the same epoch from the same enriched gas. It may also indicate a significant contribution from disrupted GCs to the stellar component of the host galaxy as might be expected in the 'failed galaxy' formation scenario for UDGs.