Dynamics of stellar disc tilting from satellite mergers

ABSTRACT The Milky Way’s stellar disc can tilt in response to torques that result from infalling satellite galaxies and their associated tidal debris. In this work, we explore the dynamics of tilting by running N-body simulations mergers an isolated, isotropic Way-like host galaxy, varying over virial mass, initial position, orbit. We develop validate a first-principles understanding govern how galaxy’s responds satellite’s dark matter (DM) find degree be large for cosmologically motivated merger histories. particular, our results suggest Galactic may still Gaia-Sausage-Enceladus, one most significant recent history. These findings have implications terrestrial direct detection experiments as changes relative location Sun with respect DM substructure left behind merging galaxy.