The Effect of Enriched Accreted Matter on the Development of Novae

TL;DR

This study investigates how the enrichment of heavy elements in accreted matter influences nova development, revealing that enrichment affects eruption features at high accretion rates and that heavy element accumulation triggers ignition.

Contribution

It introduces the impact of heavy element enrichment in accreted material on nova eruption features, especially at high accretion rates, expanding beyond the standard solar metallicity assumption.

Findings

Enrichment influences nova features at high accretion rates.

Heavy element accumulation, not just total mass, triggers thermonuclear runaway.

Effect of enrichment negligible at low accretion rates.

Abstract

The development of a nova eruption is well known to be determined by the white dwarf (WD) mass and the rate at which it accretes mass from its donor. One of the advancements in this field is the understanding that the occurrence of a nova eruption depends on the presence of heavy elements in the envelope, and that the concentration of these elements is highly dependent on the time allotted for accretion. This results in many features of the eruption being correlated with the mass fractions of heavy elements in the ejected material, however, the accreted material is always assumed to be of solar metallicity. Here we explored the entire range of accretion rates onto a 1.25$M_\odot$ WD for two cases of highly enriched accreted material and find enrichment to have an influence on certain features for high accretion rates, while the effect of enrichment on low accretion rates is negligible. We further find that the ignition of the thermonuclear runaway which is known to be dependent on the accumulation of a critical mass, is actually dependent on the accumulation of a critical amount of heavy elements.