Presentation #243.03 in the session Accreting Black Holes & Tidal Disruption Events — iPoster Session.
During the accretion process onto the supermassive black holes (SMBH) the potential energy of the gas is released, making such systems among the brightest sources in the universe. Even in case of low accretion rate, we can observe the rich variability of galactic nuclei in the whole electromagnetic spectrum. When there is a stellar-size object moving in the close vicinity of the black hole, it must perturb the accretion process in the way that can leave signatures in the observed variability.
We show the results of general-relativistic magnetohydrodynamical (GRMHD) simulations of the behaviour of the accretion disc that is perturbed by repetitive transits of a star or a secondary black hole. The perturbation diminishes the accretion rate onto the central black hole depending on the parameters of the star and its trajectory. Blobs of matter are expelled in the low-density, highly-magnetized region along the rotational axis of the black hole.
This contribution is based on a recent paper (P. Sukova et al., ApJ 917, id.43, 2021) that has been supplemented by illustrative animations.