Astronomy's current model of galaxy evolution is built on a foundation of hierarchical growth, in which small galaxies merge together to form larger ones. In addition to the simple accrual of mass, this merging process is predicted to fundamentally change the galaxies’ properties, such as dramatic morphological transformations, the triggering of bursts of star formation and high rates of accretion onto the central supermassive black hole. In this talk I will explain the physical processes behind these predictions, and present the observations that we are performing in order to test the theory. Although many of the predictions are indeed borne out by experiment, there have been some surprising conflicts as well, that demand revisions to our models of how mergers shape galaxy evolution.
Originally from the UK, Professor Sara Ellison completed her PhD at the University of Cambridge in 2000. From 2000-2003, she was an ESO fellow based in Chile, where she combined independent research with support duties at the VLT. In 2003, Professor Ellison moved to the University of Victoria to take up a Canada Research Chair in observational cosmology; she was promoted to Associate Professor in 2008 and Full Professor in 2014.