GINGA OBSERVATIONS OF THE SHAPLEY SUPERCLUSTER

We present the results of scanning and pointed X-ray observations of a region of about 40 square degrees in the vicinity of the rich cluster Shapley 8, in the Shapley Supercluster of galaxies. The Shapley Supercluster is the richest known supercluster and Shapley 8 is classified optically as richness class 4. We find no evidence for excess diffuse emission associated with the supercluster and obtain a strong limit on the total mass of X-ray emitting gas. Several new point sources have been discovered in the region and the X-ray properties of Shapley 8 have been measured for the first time. Despite its apparent high optical richness, Shapley 8 is not exceptionally luminous in X-rays, being about one third of the luminosity of the highest luminosity clusters known. We suggest that its high optical richness is in part due to neighbouring clusters, four of which are now resolved in X-rays within 2-degrees of Shapley 8.