Volkssternwarte München, Rosenheimer Str. 145h, 81671 München
The Milky Way is bound for a head-on collision with our neighbour galaxy, Andromeda. Galaxy collisions are common in the early Universe. They are thought to build up the most massive galaxies, turn spiral galaxies into elliptical ones, and trigger the strongest starburst and most active black holes. The merger of two supermassive black holes in two galaxies is also expected to emit gravitational waves, that will be detectable with future space missions. How does this spectacular phenomenon influence the life of galaxies? What can we learn by observing colliding galaxies with the largest telescopes on earth?