WALLABY early science - II. The NGC 7232 galaxy group

Journal article

We report on neutral hydrogen (HI) 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 square degrees. Analyzing a subregion of the central beams, we detect 17 HI sources. Eleven of these detections are identified as galaxies and have stellar counterparts, of which five are newly resolved HI galaxy sources. The other six detections appear to be tidal debris in the form of HI 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 HI clouds has a mass of MHI ∼ 3 × 108 M⊙ and could be the progenitor of long-lived tidal dwarf galaxy. The remaining HI 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

Authors: Lee-Waddell, K; Koribalski, B; Westmeier, T; Elagali, A; For, B

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: Oxford University Press
• Journal: Monthly Notices of the Royal Astronomical Society
• Volume: 487
• Issue: 4
• Pages: 5248–5262
• Publication date: 2019-01-05
• Acceptance date: 2018-12-22
• DOI: 10.1093/mnras/stz017
• EISSN: 1365-2966
• ISSN: 0035-8711
• Language: English
• Keywords: NGC 7232; individual; groups; galaxies; galaxies; interactions