Three-temperature radiation hydrodynamics with PLUTO

Abstract

In circumstellar disks around T Tauri stars, visible and near-infrared stellar irradiation is intercepted by dust at the disk’s optical surface and reprocessed into thermal infrared. It subsequently undergoes radiative diffusion through the optically thick bulk of the disk. The gas component, overwhelmingly dominated by mass but contributing little to the opacity, is heated primarily by gas-grain collisions. However, in hydrodynamical simulations, typical models for this heating process (local isothermality, β-cooling, and two-temperature radiation hydrodynamics) incorporate simplifying assumptions that limit their ranges of validity. To build on these methods, we developed a “three-temperature” numerical scheme, which self-consistently models energy exchange between gas, dust, and radiation, as a part of the PLUTO radiation-hydrodynamics code. With a range of test problems in 0D, 1D, 2D, and 3D, we demonstrate the efficacy of our method and make the case for its applicability across a wide range of problems in disk physics, including hydrodynamic instabilities and disk-planet interactions.