Problem-orientable numerical algorithm for modelling multi-dimensional radiative MHD flows in astrophysics -- the hierarchical solution scenario

摘要

We present a hierarchical approach for enhancing the robustness of numericalsolvers for modelling radiative MHD flows in multi-dimensions. This approach isbased on clustering the entries of the global Jacobian in a hierarchical mannerthat enables employing a variety of solution procedures ranging from a purelyexplicit time-stepping up to fully implicit schemes. A gradual coupling of theradiative MHD equation with the radiative transfer equation in higherdimensions is possible. Using this approach, it is possible to follow theevolution of strongly time-dependent flows with low/high accuracies and withefficiency comparable to explicit methods, as well as searchingquasi-stationary solutions for highly viscous flows. In particular, it is shownthat the hierarchical approach is capable of modelling the formation of jets inactive galactic nuclei and reproduce the corresponding spectral energydistribution with a reasonable accuracy.