Tidally enhanced stellar wind: a way to make the symbiotic channel to Type Ia supernova viable

TL;DR

This paper proposes that tidally enhanced stellar winds can significantly increase the white dwarf accretion rate in symbiotic systems, making the single degenerate channel a more viable pathway for Type Ia supernovae.

Contribution

It introduces a model of tidally enhanced stellar winds that extends the progenitor parameter space and increases the predicted supernova birthrate in symbiotic systems.

Findings

The model increases the SNe Ia birthrate to about 0.0069 per year.

Two observed symbiotic stars, T CrB and RS Oph, fit within the predicted progenitor parameter space.

Tidally enhanced winds extend the viable orbital period range for SNe Ia progenitors.

Abstract

In the symbiotic (or WD+RG) channel of the single degenerate scenario for type Ia supernovae (SNe Ia) the explosions occur a relatively long time after star formation. The birthrate from this channel would be too low to account for all observed SNe Ia were it not for some mechanism to enhance the rate of accretion on to the white dwarf. A tidally enhanced stellar wind, of the type which has been postulated to explain many phenomena related to giant star evolution in binary systems, can do this. Compared to mass-stripping this model extends the space of SNe Ia progenitors to longer orbital periods and hence increases the birthrate to about $0.0069\,{\rm yr^{-1}}$ for the symbiotic channel. Two symbiotic stars, T CrB and RS Oph, considered to be the most likely progenitors of SNe Ia through the symbiotic channel, are well inside the period--companion mass space predicted by our models.