2000ApJ...528..139D

We present constraints on theoretical models of Type Ia supernovae (SNe) using spatially resolved ASCA X-ray spectroscopy of three galaxy clusters: Abell 496, Abell 2199, and Abell 3571. All three clusters have central iron abundance enhancements; an ensemble of abundance ratios are used to show that most of the iron in the central regions of the clusters comes from SNe Ia. These observations are consistent with the suppressed galactic wind scenario recently proposed by the authors. At the center of each cluster, simultaneous analysis of spectra from all ASCA instruments shows that the nickel-to-iron abundance ratio (normalized by the solar ratio) is Ni/Fe~4. We use the nickel-to-iron ratio as a discriminator between SN Ia explosion models; the Ni/Fe ratio of ejecta from the ``convective deflagration'' model W7 is consistent with the observations, while those of ``delayed detonation'' models are not consistent at the 90% confidence level.