The Intrinsic Shapes of Low Surface Brightness Galaxies: a Discriminant of LSBG Formation Mechanisms

Abstract

We use the low surface brightness galaxy (LSBG) samples created from the Hyper Suprime-Cam Subaru Strategic Program (HSC-SSP, 781 galaxies), the Dark Energy Survey (DES, 20977 galaxies), and the Legacy Survey (selected via HI detection in the Arecibo Legacy Fast ALFA Survey, 188 galaxies) to infer the intrinsic shape distribution of the low surface brightness galaxy population. To take into account the effect of the surface brightness cuts employed when constructing LSBG samples, we simultaneously model both the projected ellipticity and the apparent surface brightness in our shape inference. We find that the LSBG samples are well-characterized by oblate spheroids, with no significant difference between red and blue LSBGs. This inferred shape distribution is in good agreement with similar inferences made for ultra-diffuse cluster galaxy samples, indicating that environment does not play a key role in determining the intrinsic shape of low surface brightness galaxies. We also find some evidence that LSBGs are more thickened than similarly massive high surface brightness dwarfs. We compare our results to intrinsic shape measures from contemporary cosmological simulations, and find that the observed LSBG intrinsic shapes place considerable constraints on the formation path of such galaxies. In particular, LSBG production via the migration of star formation to large radii produces intrinsic shapes in good agreement with our observational findings.

19 pages, 10 figures, accepted to ApJ

References in corpus (15)

• Forty-Seven Milky Way-Sized, Extremely Diffuse Galaxies in the Coma Cluster
• NIHAO XI: Formation of Ultra-Diffuse Galaxies by outflows
• Imfit: A Fast, Flexible New Program for Astronomical Image Fitting
• Dark Energy Survey Year 3 Results: Photometric Data Set for Cosmology
• Shadows in the Dark: Low-Surface-Brightness Galaxies Discovered in the Dark Energy Survey
• Robust HI kinematics of gas-rich ultra-diffuse galaxies: hints of a weak-feedback formation scenario
• The shapes of galaxies in the Sloan Digital Sky Survey
• The Formation of Isolated Ultra-Diffuse Galaxies in Romulus25
• 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
• Star Formation in Isolated Dwarf Galaxies Hosting Tidal Debris: Extending the Dwarf-Dwarf Merger Sequence
• The quiescent fraction of isolated low surface brightness galaxies: Observational constraints
• Detection of a Large Population of Ultra Diffuse Galaxies in Massive Galaxy Clusters: Abell S1063 and Abell 2744
• NIHAO XXIV: Rotation or pressure supported systems? Simulated Ultra Diffuse Galaxies show a broad distribution in their stellar kinematics
• An expanded catalogue of low surface brightness galaxies in the Coma cluster using Subaru/Suprime-Cam

Cited by in corpus (19)

• Observational constraints on stellar feedback in dwarf galaxies
• Implications for Galaxy Formation Models from Observations of Globular Clusters around Ultra-Diffuse Galaxies
• Origin and evolution of ultra-diffuse galaxies in different environments
• What's in a name? Quantifying the interplay between the Definition, Orientation, and Shape of Ultra-diffuse Galaxies Using the Romulus Simulations
• ELVES III: Environmental Quenching by Milky Way-Mass Hosts
• Beyond Ultra-diffuse Galaxies. I. Mass--Size Outliers among the Satellites of Milky Way Analogs
• Ultra-Diffuse Galaxies as Extreme Star-forming Environments I: Mapping Star Formation in HI-Rich UDGs
• The In-situ Origins of Dwarf Stellar Outskirts in FIRE-2
• Ultra-Diffuse Galaxies as Extreme Star-forming Environments II: Star Formation and Pressure Balance in HI-Rich UDGs
• The Nature of Low Surface Brightness Galaxies in the Hyper Suprime-Cam Survey
• The Merian Survey: Design, Construction, and Characterization of a Filter Set Optimized to Find Dwarf Galaxies and Measure their Dark Matter Halo Properties with Weak Lensing
• The Quenched Satellite Population Around Milky Way Analogs
• Ultra-Diffuse Galaxies (UDGs) with Hyper Suprime-Cam I: Revised Catalog of Coma Cluster UDGs
• No need for dark matter: resolved kinematics of the ultra-diffuse galaxy AGC 114905
• Environmental Quenching of Low Surface Brightness Galaxies near Milky Way mass Hosts
• The Formation of Dwarf Galaxy Disks
• Quenching of satellite galaxies of Milky Way analogues: reconciling theory and observations
• The dynamical lineage of ultra-diffuse galaxies from TNG50-1
• The Fornax Deep Survey (FDS) with the VST: III. Low Surface Brightness (LSB) dwarfs and Ultra Diffuse Galaxies (UDGs) in the center of the Fornax cluster