Contributed Talk - Splinter Computation

Friday, 25 September 2020, 12:09   (virtual room B)

High Resolution Parameter Study of the Vertical Shear Instability

Natascha Manger, Hubert Klahr, Wilhelm Kley and Mario Flock
CCA-Flatiron Institute and Max-Planck Institute for Astronomy Heidelberg and Tübingen University

Theoretical models of protoplanetary disks have shown the Vertical Shear Instability (VSI) to be a prime candidate to explain turbulence in the dead zone of the disk. However, simulations of the VSI have yet to show consistent levels of key disk turbulence parameters like the stress-to-pressure ratio α. In this talk, we will present a parameter study of the VSI utilizing full 2π 3D simulations of protoplanetary disks, aiming to reconcile the different reported turbulence parameters. We find that the saturated stress-to-pressure ratio in our simulations is dependent on the disk aspect ratio with a strong scaling of α∝h2.6, which is in contrast to the traditional α model, where α is assumed constant. We also observe consistent formation of large scale vortices across all investigated parameters. The vortices show uniformly aspect ratios of χ≈10 and radial widths of approximately 1.5H. With our findings, we can reconcile the different values reported for the stress-to-pressure ratio from both isothermal and full radiation hydrodynamics models, and show long-term evolution effects of the VSI that could aide in the formation of planetesimals.