Global GRMHD Simulations of Black Hole Accretion Flows: a Convergence Study

摘要: Global, general relativistic magnetohydrodynamic (GRMHD) simulations of nonradiative, magnetized disks are widely used to model accreting black holes. We have performed a convergence study GRMHD models computed with HARM3D. The span factor 4 in linear resolution, from 96x96x64 384x384x256. consider three diagnostics convergence: (1) dimensionless shell-averaged quantities such as plasma \beta; (2) the azimuthal correlation length fluid variables; and (3) synthetic spectra source including synchrotron emission, absorption, Compton scattering. Shell-averaged temperature is, except for lowest resolution run, nearly independent resolution; \beta\ decreases steadily but shows signs convergence. lengths density, internal energy, decrease show In contrast, magnetic field linearly grid size. argue by analogy local models, however, that should be achieved another 2 resolution. Synthetic are, behavior is consistent higher physical (shearing box) calculations recent nonrelativistic global studies Hawley et al. (2011).