Why Are Peculiar Type Ia Supernovae More Likely to Show the Signature of a Single-degenerate Model?

TL;DR

This paper proposes a universal spin-up/spin-down model for Type Ia supernovae, explaining why peculiar SNe Ia are more likely to exhibit signatures of the single-degenerate progenitor scenario based on initial white dwarf mass.

Contribution

It introduces a spin-up/spin-down model linking initial WD mass to SD signatures, explaining observational differences among SNe Ia.

Findings

More massive initial WDs have shorter spin-down timescales.

Hybrid carbon-oxygen-neon WDs are more likely to show SD signatures.

The model accounts for the diversity in observed SNe Ia signatures.

Abstract

Although type Ia supernovae (SNe Ia) are very useful in many astrophysical fields, their exact progenitor nature is still unclear. A basic method to distinguish the different progenitor models is to search the signal from the single degenerate (SD) model, e.g. the signal for the existence of a non-degenerate companion before or after supernova explosion. Observationally, some SNe Ia show such signal, while the others do not. Here, we propose a universal model to explain these observations based on the spin-up/spin-down model, in which a white dwarf (WD) will experience a spin-down phase before supernova explosion, and the spin-down timescale is determined by its initial mass, i.e. the more massive the initial WD, the shorter the spin-down timescale and then the more likely the SN Ia to show the SD signature. Therefore, our model predicts that the SNe Ia from hybrid carbon-oxygen-neon WDs are more likely to show the SD signature observationally, as some peculiar SNe Ia showed.