Three-temperature radiation hydrodynamics with PLUTO: Tests and applications to protoplanetary disks

TL;DR

This paper introduces a three-temperature radiation hydrodynamics scheme integrated into the PLUTO code, enabling more accurate simulations of energy exchange in protoplanetary disks, with tests demonstrating its effectiveness across multiple dimensions.

Contribution

The authors develop and validate a novel three-temperature model for radiation hydrodynamics, improving upon previous simplified methods for disk simulations.

Findings

The scheme accurately models energy exchange between gas, dust, and radiation.

Validated with tests in 0D to 3D, demonstrating robustness.

Applicable to various disk phenomena including instabilities and planet interactions.

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; this subsequently undergoes radiative diffusion through the optically thick bulk of the disk. The gas component -- overwhelmingly dominant by mass, but contributing little to the opacity -- is heated primarily by gas-grain collisions. In hydrodynamical simulations, however, typical models for this heating process (local isothermality, $\beta$-cooling, two-temperature radiation hydrodynamics) incorporate simplifying assumptions that limit their ranges of validity. To build on these methods, we develop 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 to a wide range of problems in disk physics, including hydrodynamic instabilities and disk-planet interaction.