2003/11/24 by M. Bureau, Martin Bureau, F. Walter +8
Physics and Astronomy · #Astrophysics (astro-ph) #Astrophysics and Star Formation Studies #FOS: Physical sciences #Galaxies: Formation, Evolution, Phenomena #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.48550/arxiv.astro-ph/0311539
6 pages, 3 figures, to be published in "Recycling Intergalactic and Interstellar Matter," eds. P.-A. Duc, J. Braine, & E. Brinks (ASP: San Francisco)
arxiv created 2003/11/24 · openalex publication_date 2003/11/24 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Results are presented from a wide area, high resolution HI synthesis survey of the outer regions of the nearby M81 group, where internal (galactic) and external (group-related) evolution processes can be studied simultaneously in great detail. The survey encompasses the star forming dwarf galaxies M81dwA, UGC4483, and HoII, where evidence of ram pressure stripping was recently discovered. The data do not reveal any intergalactic HI, but the outer parts of HoII are reminiscent of tidal tails. We argue however that those structures are equally consistent with the latest ram pressure models including cooling. The case for a hot intergalactic medium in this poor, spiral-only group is thus still open. The survey also puts tight constraints on possible counterparts to the local high velocity cloud population in an external group, reaching a 3 sigma column density of 1019 atom/cm2 and a 6 sigma limiting mass of 1.5x105 Msun.