Back to Search Start Over

MeerKAT-64 discovers wide-spread tidal debris in the nearby NGC 7232 galaxy group.

Authors :
Namumba, B
Koribalski, B S
Józsa, G I G
Lee-Waddell, K
Jones, M G
Carignan, C
Verdes-Montenegro, L
Ianjamasimanana, R
de Blok, W J G
Cluver, M
Garrido, J
Sánchez-Expósito, S
Ramaila, A J T
Thorat, K
Andati, L A L
Hugo, B V
Kleiner, D
Kamphuis, P
Serra, P
Smirnov, O M
Source :
Monthly Notices of the Royal Astronomical Society; Aug2021, Vol. 505 Issue 3, p3795-3809, 15p
Publication Year :
2021

Abstract

We report the discovery of large amounts of previously undetected cold neutral atomic hydrogen (H  i) around the core triplet galaxies in the nearby NGC 7232 galaxy group with MeerKAT. With a physical resolution of ∼1 kpc, we detect a complex web of low-surface-brightness H  i emission down to a 4 σ column density level of ∼1 × 10<superscript>19</superscript> cm<superscript>−2</superscript> (over 44  km s<superscript>−1</superscript>). The newly discovered H  i streams extend over ∼20 arcmin corresponding to 140 kpc in projection. This is approximately three times the H  i extent of the galaxy triplet (52 kpc). The H  i debris has an H  i mass of ∼6.6 × 10<superscript>9</superscript> M<subscript>⊙</subscript>, more than 50 per cent of the total H  i mass of the triplet. Within the galaxy triplet, NGC 7233 and NGC 7232 have lost a significant amount of H  i while NGC 7232B appears to have an excess of H  i. The H  i 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 H  i mass the NGC 7232/3 galaxy triplet is not H  i -deficient. Despite the many interactions associated to the triplet galaxies, no H  i seems to have been lost from the group (yet). [ABSTRACT FROM AUTHOR]

Details

Language :
English
ISSN :
00358711
Volume :
505
Issue :
3
Database :
Complementary Index
Journal :
Monthly Notices of the Royal Astronomical Society
Publication Type :
Academic Journal
Accession number :
151270531
Full Text :
https://doi.org/10.1093/mnras/stab1524