[ITAL]ROSAT[/ITAL] and [ITAL]BeppoSAX[/ITAL] Evidence of Soft X-Ray Excess Emission in the Shapley Supercluster: A3571, A3558, A3560, and A3562

Excess soft X-ray emission in clusters of galaxies has so far been detectedfor sources that lie along lines-of-sight to very low Galactic HI columndensity (such as Coma, A1795, A2199 and Virgo, N_H 0.9-2.0 10^{20} cm-2). Weshow that the cluster soft excess emission can be investigated even at higherN_H, which provides an opportunity for investigating soft X-ray emissioncharacteristics among a large number of clusters. The ROSAT PSPC 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 excessemission in the 1/4 keV band. We were able to confirm the finding for the caseof A3571 by a pointed SAX observation. Within the current sample the soft X-rayflux is again found to be consistently above the level expected from a hotvirialized plasma. The data quality is however insufficient to enable adiscrimination between alternative models of the excess low energy flux.Comment: ApJL in press, 5 figure