Multi-Dimensional Radiative Transfer Calculations of Double Detonations of Sub-Chandrasekhar-Mass White Dwarfs

TL;DR

This study presents multi-dimensional radiative transfer models of double detonation supernovae, showing they can explain most observed Type Ia supernovae across various luminosities, with some spectral discrepancies remaining.

Contribution

First comprehensive suite of light curves and spectra from multi-dimensional models of thin-shell double detonations in sub-Chandrasekhar white dwarfs, aligning with observed supernova diversity.

Findings

Models broadly match observed supernova light curves and spectra.

Double detonations can account for most Type Ia supernovae.

Some spectral velocity and color discrepancies remain.

Abstract

Study of the double detonation Type Ia supernova scenario, in which a helium shell detonation triggers a carbon core detonation in a sub-Chandrasekhar-mass white dwarf, has experienced a resurgence in the past decade. New evolutionary scenarios and a better understanding of which nuclear reactions are essential have allowed for successful explosions in white dwarfs with much thinner helium shells than in the original, decades-old incarnation of the double detonation scenario. In this paper, we present the first suite of light curves and spectra from multi-dimensional radiative transfer calculations of thin-shell double detonation models, exploring a range of white dwarf and helium shell masses. We find broad agreement with the observed light curves and spectra of non-peculiar Type Ia supernovae, from subluminous to overluminous subtypes, providing evidence that double detonations of sub-Chandrasekhar-mass white dwarfs produce the bulk of observed Type Ia supernovae. Some discrepancies in spectral velocities and colors persist, but these may be brought into agreement by future calculations that include more accurate initial conditions and radiation transport physics.