METAL ENRICHMENT OF THE INTRACLUSTER MEDIUM FROM PROTOGALAXIES AND THE GAMMA-RAY BURSTERS

Metal enrichment of clusters of galaxies by protogalactic star formation is discussed. We show that the observational requirement of metal ejection from protogalaxies into the intracluster medium (ICM) suggests pregalactic massive star formation bursts in the extended halo of protogalaxies. Our results predict that galaxies have an extended halo populated with a number of supernova remnants. The predicted large radius of the extended halo of our Galaxy is consistent with the distribution of gamma-ray bursters observed by BATSE on the Compton Gamma Ray Observatory satellite, if neutron stars possibly formed in the extended halo of the Galaxy are the source of gamma-ray bursters.