Cosmic Type Ia SN rate and constraints on SN Ia progenitors

Type Ia supernovae play a key role in the evolution of galaxies by polluting the interstellar medium with a fraction of iron peak elements larger than that released in the core collapse supernova events. Their light-curve, moreover, is widely used in cosmological studies as it constitutes a reliable distance indicator at extra-galactic scales. Among the mechanisms proposed to explain the Type Ia SNe, the single and double degenerate channels are thought to be the dominant ones, which imply a different distribution of time delays between the progenitor formation and the explosion. In this paper, we aim at determining the dominant mechanism by comparing a compilation of observed type Ia SN with our predictions, and evaluating the relative contribution of both channels. By using a least-squares fitting procedure, we model the observations of type Ia SN rates assuming different combinations of three recent cosmic star formation rates and seven delay time distributions. The goodness of these fits are statistically quantified by the chi-squared test. Though dependent on the assumed cosmic star formation rate, we find arguments in favor of the single degenerate model. From the theoretic point of view, at least the sim 30 Type Ia SN must have been produced through the single degenerate channel to account for the observations. The wide double degenerate scenario mechanism slightly under-predicts the observations at redshift z>1, unless the cosmic SFR flattens in that regime. On the contrary, although the purely close double degenerate scenario can be ruled out, we cannot rule out a mixed scenario with single and double degenerate progenitors.