A Comparison of Metal Enrichment Histories in Rich Clusters and Individual Luminous Elliptical Galaxies

Hot, X-ray emitting gaseous halos around massive elliptical galaxies are aresult of both stellar mass loss and inflow toward the overdensity from whichgiant ellipticals and their associated galaxy groups formed. The metalabundance in this gas contains important information about early star formationand past supernova activity. We find that Type II supernovae based on aSalpeter IMF, plus a small number of additional Type Ia supernovae, can explainthe the density, temperature and abundance profiles currently observed ingaseous halos around massive ellipticals. Within the central, optically brightregions of luminous ellipticals, approximately half of the interstellar iron isproduced by Type Ia supernovae and half by mass lost from evolving stars whichwere originally enriched by Type II supernovae. However, iron and siliconabundances in the intracluster gas within rich clusters suggest enrichment by alarger number of supernovae per unit optical light than we require for massiveellipticals, either more Type Ia or more Type II from a flatter IMF. Since theenrichment histories of massive ellipticals and rich clusters are fundamentallydifferent, E and SO galaxies may not be the only sources of metal enrichment inrich cluster gas.Comment: 24 pages in AASTEX LaTeX, 8 figures; accepted by Astrophysical Journa