Evidence for Accelerated Radioactive Decay (ARD) Models of Type I Supernova Lightcurves in the Low Redshift Universe
Abstract
Forty years ago Van Hise [ApJ 192 (1974) 657-659] observed that the post peak light curve for the Type I supernova SN1937C is well represented by a sum of two exponentials with half lives which are ~ 0.75 of the terrestrial half lives of 56Ni and 56Co in the beta decay chain 56Ni → 56Co → 56Fe. Thirty nine years ago Leventhal and McCall [Nature 255 (1975) 690-692] proposed a fully convective, radioactive white dwarf model to account for the observed accelerated decay. Thirty eight years ago ARD models were tested by Rust, et al. [Nature 262 (1976) 118-120] on the data from the 15 fragmentary light curves available at that time. The results offered significant but not overwhelming support for ARD models. In this paper we present a new mathematical model for Type I lightcurves and fit that model, using only 6 free parameters, to an extensive collection of higher quality lightcurves that have been measured over the last 38 years. The fits all capture more than 99% of the total variance in the measured data, thus establishing the reality of an ARD lightcurve model. These new results provide a much improved Phillips relation for calibrating the extragalactic distance scale and testing other cosmological relations.
- Publication:
-
American Astronomical Society Meeting Abstracts #224
- Pub Date:
- June 2014
- Bibcode:
- 2014AAS...22412121R