2025/07/22 by Amir Michaelis, Michaelis, Amir, Hagai B. Perets +1
Physics and Astronomy · #FOS: Physical sciences #Gamma-ray bursts and supernovae #High Energy Astrophysical Phenomena (astro-ph.HE) #Solar and Stellar Astrophysics (astro-ph.SR)
paper · pdf · doi:10.48550/arxiv.2507.16907
openalex publication_date 2025/07/22 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/03
Type Ia supernovae (SNe Ia) are a critical tool for cosmology and galactic enrichment, yet the progenitor systems of normal 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. Here, we present 3D hydrodynamic simulations that resolve 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 solar mass 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.