Implications for Galaxy Formation Models from Observations of Globular Clusters around Ultra-Diffuse Galaxies

Abstract

We present an analysis of Hubble Space Telescope observations of globular clusters (GCs) in six ultra-diffuse galaxies (UDGs) in the Coma cluster, a sample that represents UDGs with large effective radii ($R_{\mathrm{e}}$), and use the results to evaluate competing formation models. We eliminate two significant sources of systematic uncertainty in the determination of the number of GCs, $N_{\mathrm{GC}}$ by using sufficiently deep observations that (i) reach the turnover of the GC luminosity function and (ii) provide a sufficient number of GCs with which to measure the GC number radial distribution. We find that $N_{\mathrm{GC}}$ for these galaxies is on average $\sim$20, which implies an average total mass, $M_{\mathrm{total}}$, $\sim$ $10^{11}$ $M_{\odot }$ when applying the relation between $N_{\mathrm{GC}}$ and $M_{\mathrm{total}}$. This value of $N_{\mathrm{GC}}$ lies at the upper end of the range observed for dwarf galaxies of the same stellar mass and is roughly a factor of two larger than the mean. The GC luminosity function, radial profile and average colour are more consistent with those observed for dwarf galaxies than with those observed for the more massive ($L^{\ast }$) galaxies, while both the radial and azimuthal GC distributions closely follow those of the stars in the host galaxy. Finally, we discuss why our observations, specifically the GC number and GC distribution around these six UDGs, pose challenges for several of the currently favoured UDG formation models.

Accepted for publication in MNRAS

References in corpus (34)

• The NumPy array: a structure for efficient numerical computation
• K-corrections and filter transformations in the ultraviolet, optical, and near infrared
• Evolutionary Stellar Population Synthesis with MILES. Part I: The Base Models and a New Line Index System
• UV-extended E-MILES stellar population models: young components in massive early-type galaxies
• Forty-Seven Milky Way-Sized, Extremely Diffuse Galaxies in the Coma Cluster
• The ACS Virgo Cluster Survey XV. The Formation Efficiencies of Globular Clusters in Early-Type Galaxies: The Effects of Mass and Environment
• The ACS Virgo Cluster Survey. XII. The Luminosity Function of Globular Clusters in Early Type Galaxies
• 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
• Galactic Dark Matter Halos and Globular Cluster Populations. III: Extension to Extreme Environments
• Extensive Globular Cluster Systems Associated with Ultra Diffuse Galaxies in the Coma Cluster
• The E-MOSAICS project: tracing galaxy formation and assembly with the age-metallicity distribution of globular clusters
• The formation and evolution of low-surface-brightness galaxies
• The Globular Cluster Luminosity Function and Specific Frequency in Dwarf Elliptical Galaxies
• The Next Generation Virgo Cluster Survey (NGVS). XXX. Ultra-Diffuse Galaxies and their Globular Cluster Systems
• Robust HI kinematics of gas-rich ultra-diffuse galaxies: hints of a weak-feedback formation scenario
• Globular Cluster Systems in Brightest Cluster Galaxies: A Near-Universal Luminosity Function?
• The nearest ultra diffuse galaxy: UGC2162
• Observational Properties of Ultra-Diffuse Galaxies in the Field: Field-UDGs are Predominantly Blue and Starforming
• The evolution of ultra-diffuse galaxies in nearby galaxy clusters from the Kapteyn IAC WEAVE INT Clusters Survey ($\text{KIWICS}$)
• Discovery of a red ultra-diffuse galaxy in a nearby void based on its globular cluster luminosity function
• The Globular Cluster Systems in the Coma Ellipticals. IV: WFPC2 Photometry for Five Giant Ellipticals
• Quiescent Ultra-diffuse galaxies in the field originating from backsplash orbits
• Ultra diffuse galaxies in the MATLAS low-to-moderate density fields
• Introducing the LBT Imaging of Galactic Halos and Tidal Structures (LIGHTS) survey. A preview of the low surface brightness Universe to be unveiled by LSST
• A spectroscopic study of MATLAS-2019 with MUSE: an ultra-diffuse galaxy with an excess of old globular clusters
• The first detection of ultra-diffuse galaxies in the Hydra I cluster from VEGAS survey
• Newly discovered dwarf galaxies in the MATLAS low density fields
• Clues to the nature of ultra diffuse galaxies from estimated galaxy velocity dispersions
• On the Stellar Kinematics and Mass of the Virgo Ultra-Diffuse Galaxy VCC 1287
• The ACS Fornax Cluster Survey. III. Globular Cluster Specific Frequencies of Early-Type Galaxies
• The Intrinsic Shapes of Low Surface Brightness Galaxies: a Discriminant of LSBG Formation Mechanisms
• The Archetypal Ultra-Diffuse Galaxy, Dragonfly 44, is not a Dark Milky Way
• Ultraviolet and X-ray Properties of Coma's Ultra-Diffuse Galaxies

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