Some First Steps Towards a Radiation GRMHD Code: Radiative Effects on Accretion Rate onto a Kerr Black Hole

TL;DR

This paper explores the impact of radiation on accretion processes around Kerr black holes using a new radiative GRMHD code, revealing that radiation significantly influences accretion flow dynamics in simulations.

Contribution

It introduces a radiative GRMHD code operating in the diffusion approximation and compares its results with existing non-radiative models, highlighting the importance of radiative effects.

Findings

Radiative effects can significantly regulate accretion flow.

Preliminary results show differences in accretion rates with radiation included.

The new code provides a foundation for more detailed radiative accretion studies.

Abstract

The role of radiation in general relativistic magnetohydrodynamic (GRMHD) accretion simulations is discussed through axisymmetric simulations of the evolution of an initial torus seeded with a weak magnetic field. The paper compares and contrasts the rate of accretion onto a Kerr black hole and mass flux out out of the initial torus at large radii in the GRMHD code of De Villiers and Hawley and a newly developed radiative GRMHD code. This rGRMHD code currently operates in the diffusion approximation, restricting the study of radiative effects to the bound portion of the accretion disk/jet system. However, these preliminary findings suggest that radiative effects do play a potentially significant role in regulating the accretion flow.