83 citations · 132 across the 2 of their papers we have counts for
6 papers · 1 filter
Orbital Advection by Interpolation: A Fast and Accurate Numerical Scheme for Super-Fast MHD Flows
Bryan M. Johnson, Xiaoyue Guan, Charles F. Gammie
In numerical models of thin astrophysical disks that use an Eulerian scheme, gas orbits supersonically through a fixed grid. As a result the time step is sharply limited by the Cou…
Vortices in Thin, Compressible, Unmagnetized Disks
Bryan M. Johnson, Charles F. Gammie
We consider the formation and evolution of vortices in a hydrodynamic shearing-sheet model. The evolution is done numerically using a version of the ZEUS code. Consistent with earl…
Turbulent Angular Momentum Transport in Weakly-Ionized Accretion Disks
Bryan Mark Johnson
Understanding the mechanism that drives accretion has been the primary challenge in accretion disk theory. Turbulence provides a natural means of dissipation and the removal of ang…
Nonlinear Stability of Thin, Radially-Stratified Disks
Bryan M. Johnson, Charles F. Gammie
We perform local numerical experiments to investigate the nonlinear stability of thin, radially-stratified disks. We demonstrate the presence of radial convective instability when…
Linear Theory of Thin, Radially-Stratified Disks
Bryan M. Johnson, Charles F. Gammie
We consider the nonaxisymmetric linear theory of radially-stratified disks. We work in a shearing-sheet-like approximation, where the vertical structure of the disk is neglected, a…
Nonlinear Outcome of Gravitational Instability in Disks with Realistic Cooling
Bryan M. Johnson, Charles F. Gammie
We consider the nonlinear outcome of gravitational instability in optically thick disks with a realistic cooling function. We use a numerical model that is local, razor-thin, and u…