22nd of January 2019 |
---|
ASKAP images of the NGC 7232 galaxy group (Part 2) |
by Karen Lee-Waddell |
Lee-Waddell et al. (2019) have used the Australian Square Kilometre
Array Pathfinder (ASKAP) to detect HI in the NGC 7232 galaxy group.
The observations were taken on behalf of WALLABY (the Widefield ASKAP
L-band Legacy All-sky Blind surveY) using 12 ASKAP antennas during
various commissioning and Early Science phases of the array. The left
panel shows ASKAP total HI intensity contours superimposed on a DSS2
coloured optical image of the NGC 7232/3 triplet. The combination of
HI and optical imaging provides a more complete picture of dynamics
occurring within the system. Three HI peaks coincide with the stellar
components of the major galaxies in the triplet. Two additional HI
clouds, C5 and C6, are clearly visible in the intervening region
connecting the northern spiral, NGC 7232B, to the other two galaxies
NGC 7232 and NGC 7233. It is likely that C6 is a progenitor of a
long-lived tidal dwarf galaxy. The right panel shows the ASKAP HI
velocity map of the NGC 7232/3 triplet showing coherent structure that
is connecting the galaxies as they interact with one another.
Reference: K. Lee-Waddell, B.S. Koribalski, T. Westmeier, A. Elagali, B.-Q. For, D. Kleiner, J.P. Madrid, A. Popping, T. N. Reynolds, J. Rhee, P. Serra, L. Shao, L. Staveley-Smith, J. Wang, M.T. Whiting, O.I. Wong, J.R. Allison, S. Bhandari, J.D. Collier, G. Heald, J. Marvil, S.M. Ord, 2019, MNRAS, in press (arXiv:1901.00241) |