Birthrates and delay times of Type Ia supernovae

TL;DR

This study uses binary population synthesis to compare theoretical models of Type Ia supernova progenitors with observed birthrates and delay times, highlighting the double-degenerate model's consistency with observations.

Contribution

It provides a detailed comparison of progenitor models' predicted SN Ia rates and delay times with observational data, emphasizing the viability of the double-degenerate model.

Findings

Galactic SN Ia birthrate from the DD model matches observations

SD model accounts for only 50-66% of observed rates

Delay time distribution from SD model shows weak bimodality

Abstract

Type Ia supernovae (SNe Ia) play an important role in diverse areas of astrophysics, from the chemical evolution of galaxies to observational cosmology. However, the nature of the progenitors of SNe Ia is still unclear. In this paper, according to a detailed binary population synthesis study, we obtained SN Ia birthrates and delay times from different progenitor models, and compared them with observations. We find that the Galactic SN Ia birthrate from the double-degenerate (DD) model is close to those inferred from observations, while the birthrate from the single-degenerate (SD) model accounts for only about 1/2-2/3 of the observations. If a single starburst is assumed, the distribution of the delay times of SNe Ia from the SD model is a weak bimodality, where the WD + He channel contributes to the SNe Ia with delay times shorter than 100Myr, and the WD + MS and WD + RG channels to those with age longer than 1Gyr.