Globular Clusters in Coma Cluster Ultra Diffuse Galaxies (UDGs): Evidence for Two Types of UDG?

Abstract

Ultra diffuse galaxies (UDGs) reveal extreme properties. Here we compile the largest study to date of 85 globular cluster (GC) systems around UDGs in the Coma cluster, using new deep ground-based imaging of the known UDGs and existing imaging from the Hubble Space Telescope of their GC systems. We find that the richness of GC systems in UDGs generally exceeds that found in normal dwarf galaxies of the same stellar mass. These GC-rich UDGs imply halos more massive than expected from the standard stellar mass-halo mass relation. The presence of such overly massive halos presents a significant challenge to the latest simulations of UDGs in cluster environments. In some exceptional cases, the mass in the GC system is a significant fraction of the stellar content of the host galaxy. We find that rich GC systems tend to be hosted in UDGs of lower luminosity, smaller size and fainter surface brightness. Similar trends are seen for normal dwarf galaxies in the Coma cluster. A toy model is presented in which the GC-rich UDGs are assumed to be `failed' galaxies within massive halos that have largely old, metal-poor, alpha-element enhanced stellar populations. On the other hand, GC-poor UDGs are more akin to normal, low surface brightness dwarfs that occupy less massive dark matter halos. Additional data on the stellar populations of UDGs with GC systems will help to further refine and test this simplistic model.

11 pages, 11 figures, accepted for publication in MNRAS

References in corpus (11)

• Forty-Seven Milky Way-Sized, Extremely Diffuse Galaxies in the Coma Cluster
• NIHAO XI: Formation of Ultra-Diffuse Galaxies by outflows
• A High Stellar Velocity Dispersion and ~100 Globular Clusters for the Ultra Diffuse Galaxy Dragonfly 44
• Extensive Globular Cluster Systems Associated with Ultra Diffuse Galaxies in the Coma Cluster
• The formation and evolution of low-surface-brightness galaxies
• A spectroscopic survey of dwarf galaxies in the Coma Cluster: Stellar populations, environment and downsizing
• The HST/ACS Coma Cluster Survey: I - Survey Objectives and Design
• Halo mass estimates from the Globular Cluster populations of 175 Low Surface Brightness Galaxies in the Fornax Cluster
• Extreme chemical abundance ratio suggesting an exotic origin for an ultra-diffuse galaxy
• NIHAO XXI: The emergence of Low Surface Brightness galaxies
• Constraining the dark matter halo mass of isolated low-surface-brightness galaxies

Cited by in corpus (5)

• The first detection of ultra-diffuse galaxies in the Hydra I cluster from VEGAS survey
• On the Stellar Kinematics and Mass of the Virgo Ultra-Diffuse Galaxy VCC 1287
• Ultra Diffuse Galaxies in the IC1459 Group from the VEGAS Survey
• An expanded catalogue of low surface brightness galaxies in the Coma cluster using Subaru/Suprime-Cam
• Understanding the Fundamental Plane and the Tully Fisher Relation