The Dynamical State of the Telescopium Galaxy Group - Deep Chandra Observations of NGC 6868 and NGC 6861
Abstract
We present results from deep Chandra observations of NGC 6868 and NGC 6861, the two dominant elliptical galaxies in the Telescopium galaxy group (Abell S0851). We examine the diffuse gas in and around these galaxies to establish the possible interactions occurring within the group. Surface brightness images exhibit bright edges and tails, which indicate that the galaxy group is not dynamically relaxed. Spectral analysis reveals a spiral of cool gas with an associated cold front edge in NGC 6868, indicative of gas sloshing initiated by a passing galaxy or subgroup. NGC 6861 shows bright, swept back arms and a broad tail of emission, both to the northwest, suggesting that it is being ram pressure stripped due to interactions with a diffuse intracluster medium as it moves to the southeast. We find evidence that the arms are composed of cool gas originating from the galaxy core, and propose that, as seen in other systems, they may be filaments that have been buoyantly lifted by putative radio lobes inflated by the central AGN. Our results are consistent with previous suggestions that NGC 6868 and NGC 6861 are the central dominant members of two distinct subgroups, which are currently merging to form the Telescopium galaxy group. This work is supported in part by the NSF REU and DOD ASSURE programs under NSF grant no. 0754568, by Chandra grant GO0-1009X issued under NASA contract NAS8-03060, and by the Smithsonian Institution.
- Publication:
-
American Astronomical Society Meeting Abstracts #217
- Pub Date:
- January 2011
- Bibcode:
- 2011AAS...21714801W