Stellar Velocity Dispersion and Dynamical Mass of the Ultra-Diffuse Galaxy NGC 5846_UDG1 from the Keck Cosmic Web Imager

Abstract

The ultra-diffuse galaxy in the NGC 5846 group (NGC 5846_UDG1) was shown to have a large number of globular cluster (GC) candidates from deep imaging as part of the VEGAS survey. Recently, Muller et al. published a velocity dispersion, based on a dozen of its GCs. Within their quoted uncertainties, the resulting dynamical mass allowed for either a dark matter free or a dark matter dominated galaxy. Here we present spectra from KCWI which reconfirms membership of the NGC 5846 group and reveals a stellar velocity dispersion for UDG1 of ${\sigma }_{GC}$ = 17 $\pm$ 2 km/s. Our dynamical mass, with a reduced uncertainty, indicates a very high contribution of dark matter within the effective radius. We also derive an enclosed mass from the locations and motions of the GCs using the Tracer Mass Estimator, finding a similar mass inferred from our stellar velocity dispersion. We find no evidence that the galaxy is rotating and is thus likely pressure-supported. The number of confirmed GCs, and the total number inferred for the system ($\sim$45), suggest a total halo mass of $\sim 2\times 10^{11}$ M${}_{\odot }$. A cored mass profile is favoured when compared to our dynamical mass. Given its stellar mass of 1.1$\times$10${}^8$ M${}_{\odot }$, NGC 5846_UDG1 appears to be an ultra-diffuse galaxy with a dwarf-like stellar mass and an overly massive halo.

arXiv comment6 pages, 5 figures, MNRAS

References in corpus (37)

• The Structure of Cold Dark Matter Halos
• The observed properties of dwarf galaxies in and around the Local Group
• The Structure of Dark Matter Haloes in Dwarf Galaxies
• Improving the full spectrum fitting method: accurate convolution with Gauss-Hermite functions
• Cosmicflows-2: The Data
• Accurate masses for dispersion-supported galaxies
• H alpha rotation curves of Low Surface Brightness galaxies
• Forty-Seven Milky Way-Sized, Extremely Diffuse Galaxies in the Coma Cluster
• The Masses of the Milky Way and Andromeda galaxies
• A mass-dependent density profile for dark matter haloes including the influence of galaxy formation
• Ultra-diffuse galaxies: the high-spin tail of the abundant dwarf galaxy population
• A High Stellar Velocity Dispersion and ~100 Globular Clusters for the Ultra Diffuse Galaxy Dragonfly 44
• A second galaxy missing dark matter in the NGC1052 group
• An overmassive Dark Halo around an Ultra-diffuse Galaxy in the Virgo Cluster
• The Formation of Ultra Diffuse Galaxies in Cored Dark Matter Halos Through Tidal Stripping and Heating
• The SLUGGS Survey: Kinematics for over 2500 Globular Clusters in Twelve Early-type Galaxies
• Metal-rich, Metal-poor: Updated Stellar Population Models for Old Stellar Systems
• Still Missing Dark Matter: KCWI High-Resolution Stellar Kinematics of NGC1052-DF2
• Extensive Globular Cluster Systems Associated with Ultra Diffuse Galaxies in the Coma Cluster
• The Globular Cluster Luminosity Function and Specific Frequency in Dwarf Elliptical Galaxies
• Spatially-resolved stellar kinematics of the ultra diffuse galaxy Dragonfly 44. I. Observations, kinematics, and cold dark matter halo fits
• The Formation of Isolated Ultra-Diffuse Galaxies in Romulus25
• High-Precision Dark Halo Virial Masses from Globular Cluster Numbers: Implications for Globular Cluster Formation and Galaxy Assembly
• Globular Clusters in Coma Cluster Ultra Diffuse Galaxies (UDGs): Evidence for Two Types of UDG?
• VEGAS: A VST Early-type GAlaxy Survey. II. Photometric study of giant ellipticals and their stellar halos
• The NGC 5846 Group: Dynamics and the Luminosity Function to M_R=-12
• Reconciling mass-estimates of ultra-diffuse galaxies
• Extreme chemical abundance ratio suggesting an exotic origin for an ultra-diffuse galaxy
• The SLUGGS Survey: The mass distribution in early-type galaxies within five effective radii and beyond
• A spectroscopic study of MATLAS-2019 with MUSE: an ultra-diffuse galaxy with an excess of old globular clusters
• Spatially Resolved Stellar Kinematics of the Ultra-Diffuse Galaxy Dragonfly 44: II. Constraints on Fuzzy Dark Matter
• The Distribution of Ultra-Diffuse and Ultra-Compact Galaxies in the Frontier Fields
• An Ultra diffuse Galaxy in the NGC 5846 group from the VEGAS survey
• On the Stellar Kinematics and Mass of the Virgo Ultra-Diffuse Galaxy VCC 1287
• Bridging the gap between low and high mass dwarf galaxies
• NIHAO XXIV: Rotation or pressure supported systems? Simulated Ultra Diffuse Galaxies show a broad distribution in their stellar kinematics
• The dark matter halo density profile, spiral arm morphology and black hole mass of M33

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