2003/12/04 by Robert Braun, Róbert Braun, David A. Thilker +3
Physics and Astronomy · #Astronomy and Astrophysical Research #Astrophysics (astro-ph) #Astrophysics and Star Formation Studies #FOS: Physical sciences #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.48550/arxiv.astro-ph/0312115
10 pages, 8 figures, to appear in "Satellites and Tidal Streams", eds. Prada, Martinez-Delgado
arxiv created 2003/12/04 · openalex publication_date 2003/12/04 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We have imaged the extended HI environment of M31 with an unprecedented combination of high resolution and sensitivity. We detect a number of distinct High Velocity Cloud components associated with M31. A sub-set of the features within 30 kpc appear to be tidal in origin. A filamentary ``halo'' component is concentrated at the M31 systemic velocity and appears to extend into a ``bridge'' connecting M31 and M33. This may represent condensation in coronal gas. A population of discrete clouds is detected out to radii of about 150 kpc. Discrete cloud line-widths are correlated with HI mass and are consistent with a 100:1 ratio of dark to HI mass. These may be the gaseous counterparts of low-mass dark-matter satellites. The combined distribution of M31's HVC components can be characterized by a spatial Gaussian of 55 kpc dispersion and yields an NHI distribution function which agrees well with that of low red-shift QSOs.