  When a star approaches a black hole closely, it may be pulled apart by
gravitational forces in a tidal disruption event (TDE). The flares produced by
TDEs are unique tracers of otherwise quiescent supermassive black holes (SMBHs)
located at the centre of most galaxies. In particular, the appearance of such
flares and the subsequent decay of the light curve are both sensitive to
whether the star is partially or totally destroyed by the tidal field. However,
the physics of the disruption and the fall-back of the debris are still poorly
understood. We are here modelling the hydrodynamical evolution of realistic
stars as they approach a SMBH on parabolic orbits, using for the first time the
moving-mesh code AREPO, which is particularly well adapted to the problem
through its combination of quasi-Lagrangian behaviour, low advection errors,
and high accuracy typical of mesh-based techniques. We examine a suite of
simulations with different impact parameters, allowing us to determine the
critical distance at which the star is totally disrupted, the energy
distribution and the fallback rate of the debris, as well as the hydrodynamical
evolution of the stellar remnant in the case of a partial disruption.
Interestingly, we find that the internal evolution of the remnant's core is
strongly influenced by persistent vortices excited in the tidal interaction.
These should be sites of strong magnetic field amplification, and the
associated mixing may profoundly alter the subsequent evolution of the tidally
pruned star.
