Vertical shear instability in two-moment radiation-hydrodynamical simulations of irradiated protoplanetary disks I. Angular momentum transport and turbulent heating

We studied the linear and nonlinear evolution of the Vertical Shear Instability (VSI) in axisymmetric models of protoplanetary disks, focusing on the transport of angular momentum, the produced temperature perturbations, and the applicability of local stability conditions. We modeled the gas-dust mixture via high-resolution two-moment (M1) radiation-hydrodynamical simulations including stellar irradiation with frequency-dependent opacities. We found that, given sufficient depletion of small grains (with a dust-to-gas mass ratio of \(10\%\) of our nominal value of \(10^{-3}\) for \(