This is a talk given at lunch time, usually in the conference room at noon.
In the last decade the potential impact of galaxy-scale outflows driven by quasars
on their environment has become widely recognized. Quasars provide radiative
feedback in the form of pressure and photo heating, and have been increasingly
The Andromeda Galaxy (M31), our nearest large galactic neighbour, offers a unique opportunity to
test how mergers affect galaxy properties. M31's stellar halo caused by the tidal disruption of