HI in Local Group analogs: what does it tell us about galaxy formation?

Abstract

We present the results of our HI survey of six loose groups of galaxies analogous to the Local Group. The survey was conducted using the Parkes telescope and the Australia Telescope Compact Array to produce a census of all the gas-rich galaxies and potential analogs to the high-velocity clouds (HVCs) within these groups down to M(HI)<10^7 M(sun) as a test of models of galaxy formation. We present the HI mass function and halo mass function for these analogous groups and compare them with the Local Group and other environments. We also demonstrate that our non-detection of HVC analogs in these groups implies that they must have low HI masses and be clustered tightly around galaxies, including around our own Milky Way, and are not distributed throughout the Local Group.

arXiv comment5 pages, To appear in ESO Astrophysics Symposia: "Groups of Galaxies in the Nearby Universe"

References in corpus (16)

• Dark Matter Substructure in Galactic Halos
• Where are the missing galactic satellites?
• The HIPASS Catalogue - I. Data Presentation
• Multi-Phase Galaxy Formation: High Velocity Clouds and the Missing Baryon Problem
• The HIPASS catalogue: Omega_HI and environmental effects on the HI mass function of galaxies
• High Velocity Clouds: Building Blocks of the Local Group
• The disruption of nearby galaxies by the Milky Way
• On the Continuing Formation of the Andromeda Galaxy: Detection of HI Clouds in the M31 Halo
• The Solar Motion Relative to the Local Group
• Squelched Galaxies and Dark Halos
• The Geometric Distance and Proper Motion of the Triangulum Galaxy (M33)
• Morphology, Environment, and the HI Mass Function
• An all-sky study of compact, isolated high-velocity clouds
• A Targeted Survey for HI Clouds in Galaxy Groups
• Where are the High Velocity Clouds in Local Group Analogs?
• SDSS Survey for Resolved Milky Way Satellite Galaxies II: High-Velocity Clouds in the Early Data Release