A Bird's Eye View of Ocular Galaxies

Abstract

Ocular galaxies are systems undergoing an in-plane, near grazing, prograde encounter. In addition to the interaction causing the formation of two long, symmetrically opposite tidal tails, during a short period after perigalacticon a characteristic "eye"- shape develops, hence the name. This short lived feature develops under certain initial conditions, so ocular galaxies set strict constraints on numerical models leading to unique fits to the observations. A summary of our results on three interacting systems, IC 2163/NGC 2207, NGC 2535/36, and NGC 5394/95, and new HST observations of IC 2163/NGC 2207 is presented.