ROSAT and BeppoSAX Evidence of Soft X-Ray Excess Emission in the Shapley Supercluster: A3571, A3558, A3560, and A3562
Abstract
Excess soft X-ray emission in clusters of galaxies has so far been detected for sources that lie along lines of sight to very low Galactic H I column density [such as Coma, A1795, A2199, and Virgo; NH~(0.9-2.0)×1020 cm-2]. We show that the cluster soft excess emission can be investigated even at higher NH, which provides an opportunity for investigating soft X-ray emission characteristics among a large number of clusters. The ROSAT Position Sensitive Proportional Counter analysis of some members of the Shapley concentration [A3571, A3558, A3560, and A3562 at NH~(4-4.5)×1020 cm-2] bears evidence for excess emission in the 1/4 keV band. We were able to confirm the finding for the case of A3571 by a pointed BeppoSAX observation. Within the current sample, the soft X-ray flux is again found to be consistently above the level expected from a hot virialized plasma. The data quality is, however, insufficient to enable a discrimination between alternative models of the excess low-energy flux.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- May 2001
- DOI:
- 10.1086/320259
- arXiv:
- arXiv:astro-ph/0103331
- Bibcode:
- 2001ApJ...552L...7B
- Keywords:
-
- Galaxies: Clusters: Individual: Name: Abell 3558;
- Galaxies: Clusters: Individual: Name: Abell 3560;
- Galaxies: Clusters: Individual: Name: Abell 3562;
- Galaxies: Clusters: Individual: Name: Abell 3571;
- Galaxies: Intergalactic Medium;
- Astrophysics
- E-Print:
- ApJL in press, 5 figures