SEARCH FOR INTRASUPERCLUSTER GAS IN THE SHAPLEY SUPERCLUSTER

We set limits to the amount of intrasupercluster gas in the Shapley su percluster, using COBE DMR data to search for the Sunyaev-Zeldovich ef fect and HEAO 1 A-2 data to search for diffuse X-ray emission. Chance alignments of the Shapley supercluster with primordial fluctuations we re taken into account in the analysis of the COBE DMR data using the t wo-point correlation function. We modeled the X-ray emission allowing for known point sources and a gradient in galactic emission. We found no evidence for intrasupercluster gas following a truncated isothermal beta model distribution. The Shapley supercluster does not hold much more hot (greater than or equal to 10 keV) large-scale diffuse intrasu percluster gas than the average baryon density derived from standard n ucleosynthesis theories.