Solar Abundances and Implications for Supernova Enrichment in the Normal SO NGC 1332 and other Early-Type Galaxies

In a Chandra ACIS-S observation of the moderate-L_{x/L_b}, normal S0 galaxy, NGC 1332, the diffuse X-ray emission comprises ∼isothermal hot gas, with a small central temperature peak, and a significant contribution from unresolved point sources. We obtain abundance constraints for the hot gas within 20 kpc (3 arcmin) for several key elements: Fe, O, Ne, Mg and Si. The Fe abundance is found to be ∼solar, and dramatically sub-solar values can be excluded at high significance. The abundance ratios, with respect to Fe, of the remaining elements were also found to be ∼solar, excepting Z_o/ZFe, which was significantly lower. Adopting standard Type Ia and Type II supernova metal yield models, these results imply a significant fraction (73±5%) of the enrichment comes from Type Ia supernovae. Although there is some scatter in this value when competing SNe yields are adopted, the picture is consistent with observations of more massive systems. These results now reveal a consistent pattern of ISM enrichment from cluster-scales down to moderate-Lx galaxies. Preliminary results for some other early-type galaxies will also be discussed. This work was funded in part through NASA Chandra award G02-3104X and NASA grant NAG5-13059.