Wandering Stars:An Origin of Escaped Populations

摘要

In [1], we show h is possible to create a wandering/escaped stellar population via a single gravitational interaction between a satellite galaxy and a Milky-Way size galaxy. We also find we can generate a larger escaping population by increasing the size (mass) of the satellite, or the eccentricity of its orbit. The energetic impulse that creates this population is the tidal force experienced by the particles trailing the satellite at perigalacticon. We predict a population of individual stars which have become unbound during the evolution of the Milky Way and which have existed several virial radii outside it for several Gigayears. They can be either energetically unbound (escapers) or bound (wandering).