VLA Imaging of HI-bearing Ultra-Diffuse Galaxies from the ALFALFA Survey

Abstract

Ultra-diffuse galaxies have generated significant interest due to their large optical extents and low optical surface brightnesses, which challenge galaxy formation models. Here we present resolved synthesis observations of 12 HI-bearing ultra-diffuse galaxies (HUDs) from the Karl G. Jansky Very Large Array (VLA), as well as deep optical imaging from the WIYN 3.5-meter telescope at Kitt Peak National Observatory. We present the data processing and images, including total intensity HI maps and HI velocity fields. The HUDs show ordered gas distributions and evidence of rotation, important prerequisites for the detailed kinematic models in Mancera Piña et al. (2019b). We compare the HI and stellar alignment and extent, and find the HI extends beyond the already extended stellar component and that the HI disk is often misaligned with respect to the stellar one, emphasizing the importance of caution when approaching inclination measurements for these extreme sources. We explore the HI mass-diameter scaling relation, and find that although the HUDs have diffuse stellar populations, they fall along the relation, with typical global HI surface densities. This resolved sample forms an important basis for more detailed study of the HI distribution in this extreme extragalactic population.

17 pages, 7 figures, 4 tables, accepted to ApJ

References in corpus (10)

• SPARC: Mass Models for 175 Disk Galaxies with Spitzer Photometry and Accurate Rotation Curves
• Forty-Seven Milky Way-Sized, Extremely Diffuse Galaxies in the Coma Cluster
• A High Stellar Velocity Dispersion and ~100 Globular Clusters for the Ultra Diffuse Galaxy Dragonfly 44
• HI holes and high-velocity clouds in the spiral galaxy NGC 6946
• Robust HI kinematics of gas-rich ultra-diffuse galaxies: hints of a weak-feedback formation scenario
• 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 ($\text{KIWICS}$)
• Mass-to-Light versus Color Relations for Dwarf Irregular Galaxies
• Self-consistent Color-Mass-to-Light-Ratio relations for Low Surface Brightness Galaxies
• The angular momentum of disc galaxies at z=1

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• Astrophysical Tests of Dark Matter Self-Interactions
• The ALFALFA Almost-Dark Galaxy AGC~229101: A Two Billion Solar Mass HI Cloud with a Very Low Surface Brightness Optical Counterpart
• Ultra-Diffuse Galaxies as Extreme Star-forming Environments I: Mapping Star Formation in HI-Rich UDGs
• Probing galaxy evolution through HI 21-cm emission and absorption: current status and prospects with the Square Kilometre Array
• No need for dark matter: resolved kinematics of the ultra-diffuse galaxy AGC 114905
• Unexpected clustering pattern in dwarf galaxies challenges formation models