Computing Supernova Collapse to Neutron Stars and Black Holes
Abstract
We present a new numerical code for spherical hydrodynamics in general relativity. The code can handle gravitational collapse to a neutron star or to a black hole without the appearance of singularities. Moreover, the variables and equations in the code are very similar to those appearing in traditional Lagrangian supernova codes. Any such existing code can thus be easily adapted to treat collapse where the final fate is uncertain and may be either a neutron star or a black hole. The code is based on the formulation of Hernandez & Misner, in which retarded time is used as coordinate. This prevents the computational grid from penetrating inside any black hole that may form. We present the equations and a complete finite difference scheme for the adiabatic evolution of a fluid that obeys a gammalaw equation of state. We summarize the results of several testbed calculations performed to check our code. We also give the transformation of the analytic OppenheimerSnyder solution for homogeneous dust collapse to our coordinate system.
 Publication:

The Astrophysical Journal
 Pub Date:
 April 1995
 DOI:
 10.1086/175563
 Bibcode:
 1995ApJ...443..717B
 Keywords:

 Black Holes (Astronomy);
 Computerized Simulation;
 Gravitational Collapse;
 Hydrodynamics;
 Neutron Stars;
 Relativity;
 Supernovae;
 Adiabatic Conditions;
 Computational Grids;
 Computer Programs;
 Cosmic Dust;
 Equations Of State;
 Finite Difference Theory;
 Lagrangian Function;
 Time;
 Astrophysics;
 BLACK HOLE PHYSICS;
 HYDRODYNAMICS;
 METHODS: NUMERICAL;
 STARS: NEUTRON;
 STARS: SUPERNOVAE: GENERAL