Meerkat-64 Discovers Wide-Spread Tidal Debris In The Nearby Ngc 7232 Galaxy Group

We report the discovery of large amounts of previously undetected cold neutral atomic hydrogen (HI) around the core triplet galaxies in the nearby NGC 7232 galaxy group with MeerKAT. With a physical resolution of similar to 1 kpc, we detect a complex web of low-surface-brightness HI emission down to a 4 sigma column density level of similar to 1 x 10(19) cm(-2) (over 44 km s(-1)). The newly discovered HI streams extend over similar to 20 arcmin corresponding to 140 kpc in projection. This is approximately three times the HI extent of the galaxy triplet (52 kpc). The HI debris has an HI mass of similar to 6.6 x 10(9) M-circle dot, more than 50 per cent of the total HI mass of the triplet. Within the galaxy triplet, NGC 7233 and NGC 7232 have lost a significant amount of HI while NGC 7232B appears to have an excess of HI. The HI deficiency in NGC 7232 and NGC 7233 indicates that galaxy-galaxy interaction in the group concentrates on this galaxy pair while the other disc galaxies have visited them over time. In comparison to the AMIGA sample of isolated galaxies, we find that with regards to its total HI mass the NGC 7232/3 galaxy triplet is not HI-deficient. Despite the many interactions associated to the triplet galaxies, no HI seems to have been lost from the group (yet).