First-Principles Turbulence-Driven Deflagration-to-Detonation Transition Mechanism for Near-Chandrasekhar Mass White Dwarf Progenitors

Abstract

Type Ia supernovae play an important role throughout astrophysics, most notably as standardizable cosmological candles. Yet their stellar progenitors and explosion mechanism remain areas of active investigation. For decades, the canonical model for normal-brightness Type Ia supernovae used in cosmology was a carbon-oxygen white dwarf accreting from a non-degenerate stellar companion and approaching the Chandrasekhar mass. Previously, all models of near-Chandrasekhar-mass supernovae invoked an ad hoc assumption for the critical process of detonation initiation and could therefore be tuned to a variety of outcomes. Here we present global three-dimensional hydrodynamical simulations of near-Chandrasekhar-mass progenitors that incorporate, for the first time, a laboratory-validated ab initio mechanism for the turbulence-driven deflagration-to-detonation transition. The detonation mechanism is highly efficient and initiates promptly relative to most prior work. Despite spanning a factor of six in central ignition density and qualitatively distinct ignition topologies, all models converge on nearly identical synthetic spectra at peak luminosity, matched spectroscopically to the overluminous SN 1999aa. This provides the first physically motivated, self-consistent pathway for delayed detonation in Type Ia supernova simulations.