Consistent estimates of (56)Ni yields for type Ia supernovae

We present (56)Ni mass estimates for seventeen well-observed type Ia supernovae determined by two independent methods. Estimates of the (56)Ni mass for each type Ia supernova are determined from (1) modeling of the late-time nebular spectrum and (2) through the combination of the peak bolometric luminosity with Arnett's rule. The attractiveness of this approach is that the comparison of estimated (56)Ni masses circumvents errors associated with the uncertainty in the adopted values of reddening and distance. We demonstrate that these two methods provide consistent estimates of the amount of (56)Ni synthesized. We also find a strong correlation between the derived (56)Ni mass and the absolute B-band magnitude (M(B)). Spectral synthesis can be used as a diagnostic to study the explosion mechanism. By obtaining more nebular spectra the Nif--M(B) correlation can be calibrated and can be used to investigate any potential systematic effects this relationship may have on the determination of cosmological parameters, and provide a new way to estimate extra-galactic distances of nearby type Ia supernovae.