Double Detonation of Sub-Chandrasekhar White Dwarfs and Subluminous Type Ia Supernovae

TL;DR

This paper explores how sub-Chandrasekhar white dwarfs can undergo double detonations triggered by helium accretion, potentially explaining subluminous Type Ia supernovae through a novel explosion mechanism.

Contribution

It introduces a model where helium accretion on sub-Chandrasekhar white dwarfs causes detonations, offering an explanation for subluminous supernovae.

Findings

Helium layer buildup can trigger detonations in sub-Chandrasekhar WDs.

Double detonation mechanism can produce subluminous Type Ia supernovae.

Energetics calculations support the plausibility of this scenario.

Abstract

Type Ia supernovae are thought to result from thermonuclear explosions of carbon-oxygen white dwarf stars. This model generally explains the observed properties with certain exceptions, like sub-luminous supernovae. Here we discuss the possibility of sub-Chandrasekhar WDs detonating due to the build up of a layer of helium on the C-O WD by accreting from a helium rich companion star to explain observed deviations such as subluminous type Ia. We also detail some of the energetics involved that will make such scenarios plausible.