Perturbing the accretion flow onto a supermassive black hole by a
  passing star
  The close neighbourhood of a supermassive black hole contains not only
accreting gas and dust, but also stellar-sized objects like stars, stellar-mass
black holes, neutron stars, and dust-enshrouded objects that altogether form a
dense nuclear star-cluster. These objects interact with the accreting medium
and they perturb the otherwise quasi-stationary configuration of the accretion
flow. We investigate how the passages of a star can influence the black hole
gaseous environment with GRMHD 2D and 3D simulations. We focus on the changes
in the accretion rate and the associated emergence of outflowing blobs of
plasma.
