A high-performance and portable asymptotic preserving radiation hydrodynamics code with the M₁ model

Aims. We present a new radiation hydrodynamics code, called "ARK-RT" which uses two-moment model with the M1 closure relation for radiative transfer. This code aims at being ready high-performance computing, on exascale architectures. Methods. The is solved using finite volume scheme. scheme asymptotic preserving to capture accurately both optically thick and thin regimes. also propose well-balanced discretization of flux source term able constant steady states discontinuities in opacity. use library Trilinos linear algebra package Kokkos allows us reach computing portability across different architectures, such as multi-core, many-core, GP-GPU. Results. ARK-RT reproduce standard tests free-streaming diffusive limits, including purely ones. Using time-implicit solver profitable soon time step given by 50-100 times larger than explicit transfer, depending preconditioner architecture. Albeit more work needed ensure stability all circumstances. ARK-RT, we study propagation an ionization front convective dense cores. show that strongly stable against perturbations even destabilizing motions. As result, presence instabilities should be interpreted caution. Overall, well-suited many astrophysical problems involving convection transfer dynamics H ii regions massive pre-stellar cores future applications could include planetary atmospheres.