Progenitors of type Ia supernovae in elliptical galaxies

TL;DR

This paper investigates the progenitors of type Ia supernovae in elliptical galaxies, finding that the single degenerate scenario cannot account for most observed supernovae due to inconsistencies with X-ray and nova observations.

Contribution

It provides new constraints on the single degenerate progenitor scenario, showing it can explain at most about 5% of type Ia supernovae in old stellar populations.

Findings

Single degenerate scenario is inconsistent with observed X-ray and nova data.

White dwarfs in binary systems can explain only ~5% of type Ia supernovae.

Most type Ia supernovae in old populations likely have different progenitors.

Abstract

Although there is a nearly universal agreement that type Ia supernovae are associated with the thermonuclear disruption of a CO white dwarf, the exact nature of their progenitors is still unknown. The single degenerate scenario envisages a white dwarf accreting matter from a non-degenerate companion in a binary system. Nuclear energy of the accreted matter is released in the form of electromagnetic radiation or gives rise to numerous classical nova explosions prior to the supernova event. We show that combined X-ray output of supernova progenitors and statistics of classical novae predicted in the single degenerate scenario are inconsistent with X-ray and optical observations of nearby early type galaxies and galaxy bulges. White dwarfs accreting from a donor star in a binary system and detonating at the Chandrasekhar mass limit can account for no more than ~5% of type Ia supernovae observed in old stellar populations.