Type Ia Supernova Explosions from Hybrid Carbon-Oxygen-Neon White Dwarf Progenitors

TL;DR

This study simulates Type Ia supernovae from hybrid white dwarf progenitors with C-O cores and O-Ne shells, revealing differences in explosion outcomes compared to traditional models, and explores their potential link to subluminous supernovae.

Contribution

First multidimensional simulations of Type Ia supernovae from hybrid C-O-Ne white dwarf progenitors, incorporating Urca process effects and comparing with standard C-O models.

Findings

Differences in $^{56}$Ni yields between hybrid and C-O white dwarf explosions.

Variability in kinetic properties of ejecta across simulations.

Potential connection of hybrid WD explosions to subluminous supernovae.

Abstract

Motivated by recent results in stellar evolution that predict the existence of hybrid white dwarf (WD) stars with a C-O core inside an O-Ne shell, we simulate thermonuclear (Type Ia) supernovae from these hybrid progenitors. We use the FLASH code to perform multidimensional simulations in the deflagration to detonation transition (DDT) explosion paradigm. Our hybrid progenitor models were produced with the MESA stellar evolution code and include the effects of the Urca process, and we map the progenitor model to the FLASH grid. We performed a suite of DDT simulations over a range of ignition conditions consistent with the progenitor's thermal and convective structure assuming multiple ignition points. To compare the results from these hybrid WD stars to previous results from C-O white dwarfs, we construct a set of C-O WD models with similar properties and similarly simulate a suite of explosions. We find that despite significant variability within each suite, trends distinguishing the explosions are apparent in their $^{56}$Ni yields and the kinetic properties of the ejecta. We comment on the feasibility of these explosions as the source of some classes of observed subluminous events.