Our Universe of Galaxies – Prof. Roger L. Davies – Philip Wetton Professsor and Head of Astrophysics, University of Oxford
Some galaxies have disks of young stars, others don’t. Some are dominated by huge central star piles whereas others are pure disks. What gives rise to this diversity of properties?
In attempting to answer this question I will describe the wide range of properties exhibited by galaxies, discuss how our view of them has changed since we first realised they are `island Universes’. It will put them in the cosmological context of the expanding Universe and show how collisions between galaxies, that were much more frequent in the distant past than they are today, have shaped the galaxy population we see today.