The physics of non-ideal general relativistic magnetohydrodynamics

A Numerical Method for General Relativistic Magnetohydrodynamics

This paper describes the development and testing of a general relativistic magnetohydrodynamic (GRMHD) code to study ideal MHD in the fixed background of a Kerr black hole. The code is a direct extension of the hydrodynamic code of Hawley, Smarr, and Wilson, and uses Evans and Hawley constrained transport (CT) to evolve the magnetic fields. Two categories of test cases were undertaken. A one di...

General relativistic hydrodynamics and magnetohydrodynamics: hyperbolic systems in relativistic astrophysics

Relativistic magnetohydrodynamics

The lowest-order description of a magnetized plasma is given by magnetohydrodynamics (MHD). However, many astrophysical plasmas (as well as some laboratory plasmas) are relativistic, in that either the thermal speed or the fluid flow speed approaches the speed of light, and conventional MHD is not consistent with special relativity. Beginning with exact laws of motion, this work derives a gener...

Can non-ideal magnetohydrodynamics solve the magnetic braking catastrophe?

We investigate whether or not the low ionisation fractions in molecular cloud cores can solve the ‘magnetic braking catastrophe’, where magnetic fields prevent the formation of circumstellar discs around young stars. We perform three-dimensional smoothed particle non-ideal magnetohydrodynamics (MHD) simulations of the gravitational collapse of one solar mass molecular cloud cores, incorporating...

RAISHIN: A High-Resolution Three-Dimensional General Relativistic Magnetohydrodynamics Code

We have developed a new three-dimensional general relativistic magnetohydrodynamic (GRMHD) code, RAISHIN, using a conservative, high resolution shock-capturing scheme. The numerical fluxes are calculated using the Harten, Lax, & van Leer (HLL) approximate Riemann solver scheme. The fluxinterpolated, constrained transport scheme is used to maintain a divergence-free magnetic field. In order to e...