Modeling the Irradiation Instability of Protoplanetary Disks

In most parts of a protoplanetary disk, the temperature is controlled by stellar irradiation. Recent work suggests that these passively heated disks may actually be unstable (Watanabe & Lin 2008, Wu & Lithwick 2021, Ueda et. al 2021). In this presentation, I describe the nature of the ‘irradiation instability’ and present a 2D model to numerically explore the robustness of this instability in protoplanetary disks. The model accounts for thermal diffusion and non-hydrostaticity. Potential consequences of the irradiation instability include ALMA rings and gaps, and vortices and turbulence.