Suzaku Observations to the Virial Radius of Fossil Group ESO3060170
Abstract
"Fossil" galaxy groups, each dominated by a relatively isolated giant elliptical galaxy, have many properties intermediate between groups and clusters of galaxies. We used the Suzaku X-ray observatory to observe the X-ray brightest fossil group, ESO 3060170, out to its virial radius. We determined the temperature, gas density, and metal abundance distributions of the intracluster gas and derived the entropy, pressure and mass profiles. The entropy and pressure profiles in the outer regions are flatter than in simulated clusters, which may indicate the gas is clumpy, as found in some massive clusters. While the gas in most groups has smaller iron mass-to-light ratios (IMLR) than in clusters, the integrated IMLR of this fossil group achieves the cluster value. Thus, unlike most groups, this fossil group has retained nearly all of its metals. A galaxy density map on a scale of 15 Mpc shows that this fossil group resides in a relatively isolated environment, unlike the filamentary structures in which clusters are embedded.
- Publication:
-
American Astronomical Society Meeting Abstracts #220
- Pub Date:
- May 2012
- Bibcode:
- 2012AAS...22051404S