Turbulent Linewidths in Protoplanetary Disks: Predictions from Numerical Simulations
June 18, 2012
Abstract: I will present recent numerical simulations of turbulence in protoplanetary disks, both in the self-gravitating regime and in the case of turbulence driven by the magnetorotational instability (MRI). From these simulations, we extract the distribution of turbulent velocities (i.e., fluctuations about the mean orbital motions) and compare with recent sub-mm observations that measure typical values for these velocities using molecular linewidths in disk atmospheres. Our simulations show general agreement between the peak of the velocity distributions and the observationally extracted values. Our calculations also make predictions as to how the typical turbulent velocities vary with disk radius, height, and inclination angle for both self-gravity and the MRI. We will test these predictions with future ALMA observations, thus constraining theoretical models for turbulence and angular momentum transport in these disks.