Constraining Type Ia Supernovae progenitors from three years of SNLS data

TL;DR

This study analyzes three years of SNLS data to detect signs of non-degenerate companions in Type Ia supernovae, constraining their contribution to less than 10-20% based on early lightcurve features.

Contribution

It introduces a method to identify binary companions in supernova progenitors by comparing observed and synthetic lightcurves, providing new constraints on progenitor models.

Findings

White dwarf-red giant binary contribution <10% at 2 sigma

No significant flux excess detected in early lightcurves

Method constrains progenitor scenarios using Kolmogorov-Smirnov tests

Abstract

While it is generally accepted that Type Ia supernovae are the result of the explosion of a carbon-oxygen White Dwarf accreting mass in a binary system, the details of their genesis still elude us, and the nature of the binary companion is uncertain. Kasen (2010) points out that the presence of a non-degenerate companion in the progenitor system could leave an observable trace: a flux excess in the early rise portion of the lightcurve caused by the ejecta impact with the companion itself. This excess would be observable only under favorable viewing angles, and its intensity depends on the nature of the companion. We searched for the signature of a non-degenerate companion in three years of Supernova Legacy Survey data by generating synthetic lightcurves accounting for the effects of shocking and comparing true and synthetic time series with Kolmogorov-Smirnov tests. Our most constraining result comes from noting that the shocking effect is more prominent in rest-frame B than V band: we rule out a contribution from white dwarf-red giant binary systems to Type Ia supernova explosions greater than 10% at 2 sigma, and than 20% at 3 sigma level.