Radiation hydrodynamics including irradiation and adaptive mesh refinement with AZEuS. I. Methods

摘要

Aims. The importance of radiation to the physical structure of protoplanetarydisks cannot be understated. However, protoplanetary disks evolve with time,and so to understand disk evolution and by association, disk structure, oneshould solve the combined and time-dependent equations of radiationhydrodynamics. Methods. We implement a new implicit radiation solver in the AZEuS adaptivemesh refinement magnetohydrodynamics fluid code. Based on a hybrid approachthat combines frequency-dependent ray-tracing for stellar irradiation withnon-equilibrium flux limited diffusion, we solve the equations of radiationhydrodynamics while preserving the directionality of the stellar irradiation.The implementation permits simulations in Cartesian, cylindrical, and sphericalcoordinates, on both uniform and adaptive grids. Results. We present several hydrostatic and hydrodynamic radiation testswhich validate our implementation on uniform and adaptive grids as appropriate,including benchmarks specifically designed for protoplanetary disks. Ourresults demonstrate that the combination of a hybrid radiation algorithm withAZEuS is an effective tool for radiation hydrodynamics studies, and producesresults which are competitive with other astrophysical radiation hydrodynamicscodes.