Thermonuclear explosions of rapidly rotating white dwarfs - II. Detonations

TL;DR

This paper investigates whether detonations of rapidly rotating white dwarfs can explain rare superluminous type Ia supernovae by analyzing their explosion products and dynamics.

Contribution

It introduces models of rotating white dwarfs and estimates their explosion outcomes, highlighting their potential to explain superluminous SNe Ia.

Findings

Rapid rotation leads to significant intermediate mass element production.

Detonations of rotating WDs can produce explosion characteristics matching rare superluminous SNe Ia.

Rotation laws influence the density stratification and explosion products.

Abstract

Context: Superluminous type Ia supernovae (SNe Ia) may be explained by super-Chandrasekhar-mass explosions of rapidly rotating white dwarfs (WDs). In a preceding paper, we showed that the deflagration scenario applied to rapidly rotating WDs generates explosions that cannot explain the majority of SNe Ia. Aims: Rotation of the progenitor star allows super-Chandrasekhar-mass WDs to form that have a shallower density stratification. We use simple estimates of the production of intermediate and iron group elements in pure detonations of rapidly rotating WDs to assess their viability in explaining rare SNe Ia. Methods: We numerically construct WDs in hydrostatic equilibrium that rotate according to a variety of rotation laws. The explosion products are estimated by considering the density stratification and by evaluating the result of hydrodynamics simulations. Results: We show that a significant amount of intermediate mass elements is produced for theoretically motivated rotation laws, even for prompt detonations of WDs. Conclusions: Rapidly rotating WDs that detonate may provide an explanation of rare superluminous SNe Ia in terms of both burning species and explosion kinematics.