Measuring mass-loss rates from Galactic satellites

We present the results of a study that uses numerical simulations to interpret observations of tidally disturbed satellites around the Milky Way. When analysing the simulations from the viewpoint of an observer, we nd a break in the slope of the star count and velocity dispersion proles in our models at the location where unbound stars dominate. We conclude that `extratidal' stars and enhanced velocity dispersions observed in the outskirts of Galactic satellites are caused by contamination by stellar debris from the tidal interaction with the Milky Way. However, a signicant bound population can exist beyond the break radius and we argue that it should not be identied with the tidal radius of the satellite.