THE EFFECTS OF CLUSTER TIDES ON DISK GALAXIES

We investigate the dynamical behaviour of disk galaxies orbiting withi n the potential well of a galaxy cluster, We focus on the morphologica l changes induced on halo+bulge+disk N-body galaxy models by cluster t ides, as well as on possible modifications to the shape of their rotat ion curves, Galaxy clusters are modelled as spherical potential wells whose mass distribution is either static or evolves slowly in accordan ce with a simple infall model, We find that galaxies can be totally di srupted if they are on nearly radial orbits or if they are accreted in to the cluster at high redshift, when clusters are denser, Less dramat ic effects are seen for galaxies on less eccentric orbits or accreted into the cluster at low redshift, although in many cases tides call le ad to a significant rearrangement of the mass of the halo, a thickenin g of the disk, and a declining rotation curve.