We report on neutral hydrogen (H I) observations of the NGC 7232 group with the Australian Square Kilometre Array Pathfinder (ASKAP). These observations were conducted as part of the Wide-field ASKAP L-Band Legacy All-sky Blind surveY (WALLABY) Early Science program with an array of 12 ASKAP antennas equipped with Phased Array Feeds, which were used to form 36 beams to map a field of view of 30 deg2. Analysing a subregion of the central beams, we detect 17 H I sources. Eleven of these detections are identified as galaxies and have stellar counterparts, of which five are newly resolved H I galaxy sources. The other six detections appear to be tidal debris in the form of H I clouds that are associated with the central triplet, NGC 7232/3, comprising the spiral galaxies NGC 7232, NGC 7232B, and NGC 7233. One of these H I clouds has a mass of MH I ∼ 3 × 108 M⊙ and could be the progenitor of a long-lived tidal dwarf galaxy. The remaining H I clouds are likely transient tidal knots that are possibly part of a diffuse tidal bridge between NGC 7232/3 and another group member, the lenticular galaxy IC 5181.
Lee-Waddell, Karen, Barbel S. Koribalski, Tobias Westmeier, Ahmed Elagali, B. Q. For, D. Kleiner, J. P. Madrid et al. "WALLABY Early Science–II. The NGC 7232 galaxy group." Monthly Notices of the Royal Astronomical Society 487, no. 4 (2019): 5248-5262. https://doi.org/10.1093/mnras/stz017
Monthly Notices of the Royal Astronomical Society