HI Mapping of Galaxies in Six GEMS Groups

Abstract

Here we present Australia Telescope Compact Array HI maps of 16 HI sources in six Group Evolution Multiwavelength Study (GEMS) groups that were previously observed with the Parkes telescope. The higher spatial resolution of the ATCA allows us to clearly identify the optical counterparts for the first time -- most being associated with low surface brightness late-type galaxies. New integrated HI maps and velocity fields for each source are presented. We find several interacting systems; one of which contains three galaxies within a common HI envelope. Extended HI structures in the sample are more consistent with tidal effects than ram pressure stripping. We identify two HI detections with previously uncatalogued optical galaxies, and add a total of six newly identified group members to the NGC 3923, 5044 and 7144 groups.