Speaker
Description
The progenitor systems of normal type Ia supernovae (SNe Ia) remain a central puzzle. The long-debated single-degenerate (SD) channel, where a white dwarf (WD) accretes mass from a companion, faces major observational conflicts. The unknown rising form the carbon ignition and detonation mechanism in sub-Chandrasekhar mass led us to run 3D hydrodynamic simulations that address these tensions by showing a fundamental dichotomy: accreting WDs predominantly ignite prematurely at sub-Chandrasekhar masses, producing low-energy, incomplete explosions consistent with Type Iax supernovae. Only WDs reaching a narrow mass threshold of 1.37 M⊙ undergo complete destruction, characteristic of normal SNe Ia. This ”safety valve” mechanism effectively recasts the SD channel as the main pathway to SNe Iax, not normal SNe Ia, providing a unified explanation for the observed scarcity of progenitor signatures in the latter and suggesting alternative channels dominate normal SNe Ia production.