Gravitational collapse of white dwarfs to neutron stars: From initial conditions to explosions with neutrino-radiation hydrodynamics simulations.

This article focuses on self-consistent simulations of the accretion-induced collapse (AIC) of massive, fully convective, non-rotating white dwarfs (WDs) with super-Chandrasekhar masses (~1.6 solar masses), investigating their collapse triggered by electron capture reactions and subsequent weak explosions. Using one-dimensional general relativistic neutrino-radiation hydrodynamics simulations with a multi-group M1 neutrino transport scheme, the study confirms that WDs with initial central densities between 1.0×10⁹ and 4.0×10⁹ g cm⁻³ collapse due to electron capture, producing proto-neutron stars and ejecta masses as low as ~10⁻⁵ to 10⁻⁴ solar masses with explosion energies around 10⁴⁶ to 10⁴⁸ erg. The simulations improve upon previous work by starting from stable hydrostatic equilibrium models, incorporating detailed neutrino physics, and employing general relativity, resulting in minimum ejecta masses one to two orders of magnitude smaller than earlier estimates and consistent with ejecta mass inferred from fast radio burst FRB 121102. The study also discusses the influence of surrounding atmosphere density on ejecta mass and notes that rotation and magnetic fields, not included here, may affect explosion outcomes.