THE HEAVY ELEMENT ABUNDANCE IN THE HOT CORONA OF THE BRIGHT ELLIPTIC GALAXY NGC 4472

From a 25 ks ROSAT PSPC observation of the elliptical galaxy NGC 4472, we measured the iron abundance with arcminute spatial resolution to a radial distance of 16' (74 kpc) in the hot corona. The heavy element abundance is roughly constant at approximately 1-2 [Fe/H]. from 4' to 16'. A comparison of these measurements to models of the heavy element enrichment of hot galactic coronae around elliptical galaxies provide s new insights and constraints for the evolution with time of the Type la supernova rate and for its present epoch value. In particular, the near-solar value of the iron abundance and its constancy throughout t he corona suggest a relatively constant supernova rate over time with a present epoch value at the low end of the range derived by van den B ergh & Tammann.