Consistent estimates of56Ni yields for type la supernovae

Abstract

Aims: We present 56Ni mass estimates for seventeen well-observed type la supernovae determined by two independent methods. Methods: Estimates of the 56Ni mass for each type la 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 56Ni masses circumvents errors associated with the uncertainty in the adopted values of reddening and distance. Results: We demonstrate that these two methods provide consistent estimates of the amount of 56Ni synthesized. We also find a strong correlation between the derived 56Ni mass and the absolute B-band magnitude (MB). Conclusions: Spectral synthesis can be used as a diagnostic to study the explosion mechanism. By obtaining more nebular spectra the 56Ni-MB correlation can be calibrated, and be used to investigate any potential systematic effects this relationship may have upon the determination of cosmological parameters, and provide a new manner to estimate extra-galactic distances of nearby type la supernovae. © ESO 2006.