WALLABY Early Science – II. The NGC 7232 galaxy group. Issue 4 (5th January 2019)

• Record Type: Journal Article
• Authors: Lee-Waddell, K; Koribalski, B S; Westmeier, T; Elagali, A; For, B-Q; Kleiner, D; Madrid, J P; Popping, A; Reynolds, T N; Rhee, J; Serra, P; Shao, L; Staveley-Smith, L; Wang, J; Whiting, M T; Wong, O I; Allison, J R; Bhandari, S; Collier, J D; Heald, G; Marvil, J; Ord, S M
• Is Part Of: Monthly notices of the Royal Astronomical Society. Volume 487:Issue 4(2019)
• Page Start: 5248
• Page End: 5262
• Publication Date: 2019-01-05
• Subjects: galaxies: groups: individual: NGC 7232 -- galaxies: interactions; Astronomy -- Periodicals; Periodicals; 520.5
• DOI: 10.1093/mnras/stz017
• Languages: English
• ISSNs: 0035-8711

Abstract

Abstract: 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 deg 2 . 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 × 10 8 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.