Fully General Relativistic Simulations of Core-Collapse Supernovae with An Approximate Neutrino Transport

TL;DR

This paper presents the first multi-dimensional general relativistic simulations of core-collapse supernovae with an approximate neutrino transport scheme, revealing the combined effects of GR and 3D hydrodynamics on explosion conditions.

Contribution

It introduces a new GR hydrodynamics code with approximate neutrino transport and demonstrates its application to early supernova dynamics, highlighting the impact of GR and 3D effects.

Findings

GR increases neutrino luminosity and energy due to more compact cores.

3D models favor conditions for neutrino-driven explosions.

GR and 3D together enhance the likelihood of successful supernova explosions.

Abstract

We present results from the first generation of multi-dimensional hydrodynamic core-collapse simulations in full general relativity (GR) that include an approximate treatment of neutrino transport. Using a M1 closure scheme with an analytic variable Eddington factor, we solve the energy-independent set of radiation energy and momentum based on the Thorne's momentum formalism. To simplify the source terms of the transport equations, a methodology of multiflavour neutrino leakage scheme is partly employed. Our newly developed code is designed to evolve the Einstein field equation together with the GR radiation hydrodynamic equations. We follow the dynamics starting from the onset of gravitational core-collapse of a 15 $M_{\odot}$ star, through bounce, up to about 100 ms postbounce in this study to study how the spacial multi-dimensionality and GR would affect the dynamics in the early postbounce phase. Our 3D results support the anticipation in previous 1D results that the neutrino luminosity and average neutrino energy of any neutrino flavor in the postbounce phase increase when switching from SR to GR hydrodynamics. This is because the deeper gravitational well of GR produces more compact core structures, and thus hotter neutrino spheres at smaller radii. By analyzing the residency timescale to the neutrino-heating timescale in the gain region, we show that the criterion to initiate neutrino-driven explosions can be most easily satisfied in 3D models, irrespective of SR or GR hydrodynamics. Our results suggest that the combination of GR and 3D hydrodynamics provides the most favorable condition to drive a robust neutrino-driven explosion.