WALLABY Pre-Pilot Survey: HI Content of the Eridanus Supergroup
  We present observations of the Eridanus supergroup obtained with the
Australian Square Kilometre Array Pathfinder (ASKAP) as part of the pre-pilot
survey for the Widefield ASKAP L-band Legacy All-sky Blind Survey (WALLABY).
The total number of detected HI sources is 55, of which 12 are background
galaxies not associated with the Eridanus supergroup. Two massive HI clouds are
identified and large HI debris fields are seen in the NGC 1359 interacting
galaxy pair, and the face-on spiral galaxy NGC 1385. We describe the data
products from the source finding algorithm and present the basic parameters.
The presence of distorted HI morphology in all detected galaxies suggests
ongoing tidal interactions within the subgroups. The Eridanus group has a large
fraction of HI deficient galaxies as compared to previously studied galaxy
groups. These HI deficient galaxies are not found at the centre of the group.
We find that galaxies in the Eridanus supergroup do not follow the general
trend of the atomic gas fraction versus stellar mass scaling relation, which
indicates that the scaling relation changes with environmental density. In
general, the majority of these galaxies are actively forming stars.
