The magnetorotational instability (MRI), also known as the Balbus-Hawley instability, is thought responsible for the initiation of turbulence and angular momentum transport in astrophysical disks. In work led by Jake Simon and Kris Beckwith, we are using the Athena MHD code to study the non-linear evolution of the MRI in local and global geometry. We are interested both in the limit of ideal MHD, appropriate for well-ionized disks around black holes and compact objects, and the non-ideal MHD case relevant to protoplanetary disks where the effects of Ohmic and ambipolar diffusion are important.
The movie shows the evolution of density and magnetic fields from a large shearing box simulation of the MRI. Details of the simulations are discussed in Turbulent Linewidths in Protoplanetary Disks: Predictions from Numerical Simulations (Jacob B. Simon, Philip J. Armitage and Kris Beckwith, ApJ, submitted), and in Resistivity-driven State Changes in Vertically Stratified Accretion Disks (Jacob B. Simon, John F. Hawley and Kris Beckwith).