Simulations of MHD processes in the vicinity of black holes and neutron stars, and their astrophysical interpretation

The main aim of the project is to study new phenomena in the accretion physics in the strong-gravity field of compact objects, taking into account current and near-future observational possibilities to confront our model predictions. First, we will extend our present study of low-angular momentum accretion flows and of the behaviour of shocks, in particular by including the magnetic field into the numerical simulations in HARM. Then, we will perform semi-analytical calculations and simulations of the collapse of massive stars into a black hole to determine the bounds of the rotation of the stellar envelope that can meet the LIGO/VIRGO constraints on the mass and spin of black holes. Subsequently, we will perform a set of full numerical hydrodynamical simulations of the collapse of a star in a non-stationary Kerr metric with the grid of models of the pre-supernova stars with different metallicity and density profiles using the HARM code. Furthermore, relativistic hydrodynamical simulations in the Kerr metric of the tidal disruption event of a close passage of a star around a supermassive black hole will be performed using the HARM code. In addition, we will also focus on the study of the interaction of neutron stars with the hot diluted plasma in the central part of our Galaxy in the vicinity of Sgr A* and the estimate of the expected number of neutron star magnetosphere cavities in the accretion flow. We will pay a special attention to the mutual comparison between the studied theoretical models and simulations with the prepared Athena mission with respect to the possibilities of observations of these objects. Numerical simulations will be performed on our own clusters (e.g. Oasa, Virgo, CFT Gold) and also on the supercomputers, which are available through computational grants (Cyfonet, PL-Grid).