The "Sandwich Mode" of the Vertical Shear Instability in Simulations of Protoplanetary Disks
Thomas Pfeil and Hubert Klahr
Max Planck Institute for Astronomy
The Vertical Shear Instability (VSI) is a source of non-MHD turbulence in protoplanetary disks that is crucially dependent on the fast thermal relaxation of the gas and dust. Previous numerical studies of isothermal disks have shown its potential to form long-lived anticyclonic vortices, which could be of importance for the process of planet formation. In this talk, I present two- and three-dimensional hydrodynamics simulations of stratified protoplanetary disks. Our set-ups include a novel, more realistic thermal relaxation prescription that models the optically thin and optically thick regimes under consideration of the thermal dust-to-gas coupling (Malygin et al. 2017). We find the VSI being active in certain layers of the disk and being suppressed elsewhere due to the collisional decoupling of dust and gas. Long-lived anticyclonic vortices emerge, potentially acting as sites of dust concentration and planetesimal formation.