2001/03/21 by Massimiliano Bonamente, M. Bonamente, R. Lieu +5 · 3 citations
Physics and Astronomy · #Astronomy and Astrophysical Research #Astrophysical Phenomena and Observations #Galaxies: Formation, Evolution, Phenomena #astro-ph
paper · pdf · doi:10.1086/320259
ApJL in press, 5 figures
arxiv created 2001/03/21 · openalex publication_date 2001/05/01 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/31
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; N H ~ (0.9-2.0) × 10 20 cm -2 ]. We show that the cluster soft excess emission can be investigated even at higher N H , 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 N H ~ (4-4.5) × 10 20 cm -2 ] bears evidence for excess emission in the 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.