BHAC

Responsible Partners: GUF

BHAC is a multidimensional General Relativistic Magnetohydrodynamics (GRMHD) code that is mainly used to study accretion flows onto compact objects. BHAC has been designed to solve the GRMHD equations in arbitrary (stationary) space-times/coordinates and exploits AMR techniques with an oct-tree block-based approach provided by the MPI-AMRVAC framework. Originally designed to study Black Hole (BH) accretion in ideal GRMHD, BHAC has been extended to incorporate nuclear equations of state, neutrino leakage, charged and purely geodetic test particles, and non-black hole fully numerical metrics.

BHAC has been employed in a number of studies of accretion into supermassive black holes and other compact objects. In addition, BHAC’s results, after a General-Relativistic Ray-Tracing (GRRT) post-processing, can be used to compute synthetic observable images of BH shadows and the surrounding accretion flows. These calculations are performed with the GRRT Black Hole Observations in Stationary Spacetimes (BHOSS) code. The GRMHD simulation data produced by BHAC are used as an input for BHOSS to produce accretion flow and BH shadow images. A high-level description of the code and the main algorithms can be found in §4 of the deliverable D1.2 (see deliverable section).

BHAC is publicly available on github
https://github.com/amrvac/amrvac