The number of progenitors in the core - degenerate scenario for type Ia supernovae

TL;DR

This study estimates the number of type Ia supernovae produced in the core-degenerate scenario, finding it consistent with observations, and suggests this pathway may significantly contribute to SN Ia formation.

Contribution

It introduces a simplified population synthesis model that effectively predicts SN Ia rates in the core-degenerate scenario, highlighting its potential importance.

Findings

Predicted SN Ia rate matches observed values within uncertainties.

The core-degenerate scenario could be a major channel for SN Ia formation.

A simple stellar evolution model can explain observed supernova rates.

Abstract

We calculate the expected number of type Ia supernovae (SN Ia) in the core-degenerate (CD) scenario and find it to match observations within the uncertainties of the code. In the CD scenario the super-Chandrasekhar mass white dwarf (WD) is formed at the termination of the common envelope phase from a merger of a WD companion with the hot core of a massive asymptotic giant branch (AGB) star. We use a simple population synthesis code that avoids the large uncertainties involved in estimating the final orbital separation of the common envelope evolution. Instead, we assume that systems where the core of the secondary AGB star is more massive than the WD remnant of the primary star merge at the termination of the common envelope phase. We also use a simple prescription to count systems that have strong interaction during the AGB phase, but not during the earlier red giant branch (RGB) phase. That a very simple population synthesis code that uses the basics of stellar evolution ingredients can match the observed rate of SN Ia might suggest that the CD-scenario plays a major role in forming SN Ia.