GR1D - A New Open-Source Spherically-Symmetric Code for Stellar Collapse to Neutron Stars and Black Holes.

Evan O'Connor and Christian D. Ott
Class. Quant. Grav., 27 114103, 2010.



We present the new open-source spherically-symmetric general-relativistic (GR) hydrodynamics code GR1D. It is based on the Eulerian formulation of GR hydrodynamics (GRHD) put forth by Romero-Ibanez-Gourgoulhon and employs radial-gauge, polar-slicing coordinates in which the 3+1 equations simplify substantially. We discretize the GRHD equations with a finite-volume scheme, employing piecewise-parabolic reconstruction and an approximate Riemann solver. GR1D is intended for the simulation of stellar collapse to neutron stars and black holes and will also serve as a testbed for modeling technology to be incorporated in multi-D GR codes. Its GRHD part is coupled to various finite-temperature microphysical equations of state in tabulated form that we make available with GR1D. An approximate deleptonization scheme for the collapse phase and a neutrino-leakage/heating scheme for the postbounce epoch are included and described. We also derive the equations for effective rotation in 1D and implement them in GR1D. We present an array of standard test calculations and also show how simple analytic equations of state in combination with presupernova models from stellar evolutionary calculations can be used to study qualitative aspects of black hole formation in failing rotating core-collapse supernovae. In addition, we present a simulation with microphysical EOS and neutrino leakage/heating of a failing core-collapse supernova and black hole formation in a presupernova model of a 40 solar mass zero-age main-sequence star. We find good agreement on the time of black hole formation (within 20%) and last stable protoneutron star mass (within 10%) with predictions from simulations with full Boltzmann neutrino radiation hydrodynamics.


Here we provide the source code (v1.03, Jan 8, 2011) for GR1Dv1.03 (tar.bz2). GR1D requires a FORTRAN90 compiler and HDF5 libraries to be installed. For a detailed description of GR1D (and updates from previous version) please refer to the README (pdf) file which is also available in the above package. (previous versions, GR1Dv1.0, GR1Dv1.01, GR1Dv1.02)

While GR1D is open source, its copyright is held by Evan O’Connor and Christian D. Ott. In the absence of suitable open scientific software licenses, we release this version of GR1D to the community under the Creative Commons attribution-noncommercial-share alike license:

Essentially, you may use GR1D, but must make reference to our work, must not use GR1D for commercial purposes, and any code including or using our routines or part of them may be made publically available, and if so, only under the same license.

When using GR1D in published work, please make reference to the paper describing it:

Evan O’Connor and Christian D. Ott, A New Spherically-Symmetric General Relativistic Hydrodynamics Code for Stellar Collapse to Neutron Stars and Black Holes, Class. Quant. Grav., 27 114103, 2010.