GenASiS: General Astrophysical Simulation System. II. Self-gravitating Baryonic Matter

TL;DR

GenASiS is a simulation code designed for astrophysical phenomena like supernovae, with new capabilities for modeling self-gravitating baryonic matter, validated through tests and benchmark simulations.

Contribution

This paper introduces new features for modeling self-gravitating baryonic matter in the GenASiS code, including microphysical equations of state and gravitational collapse simulations.

Findings

Prompt, spherically symmetric explosions observed in simulations

Explosion characteristics inversely related to progenitor mass

Benchmark tests established for code validation

Abstract

GenASiS (General Astrophysical Simulation System) is a code being developed initially and primarily, though not exclusively, for the simulation of core-collapse supernovae on the world's leading capability supercomputers. This paper -- the second in a series -- documents capabilities for Newtonian self-gravitating fluid dynamics, including tabulated microphysical equations of state treating nuclei and nuclear matter (`baryonic matter'). Computation of the gravitational potential of a spheroid, and simulation of the gravitational collapse of dust and of an ideal fluid, provide tests of self-gravitation against known solutions. In multidimensional computations of the adiabatic collapse, bounce, and explosion of spherically symmetric pre-supernova progenitors -- which we propose become a standard benchmark for code comparisons -- we find that the explosions are prompt and remain spherically symmetric (as expected), with an average shock expansion speed and total kinetic energy that are inversely correlated with the progenitor mass at the onset of collapse and the compactness parameter.