Jeyhan Kartaltepe

National Optical Astronomy Observatory

"How Cosmic Collisions Shape the Universe"

Abstract: Galaxy mergers and interactions are thought to play a key role in the evolution of galaxies. These collisions can affect many important galaxy properties, such as their physical structure, their star formation rates, and the growth of their central black holes. However, the details of this role, and how it has changed over the age of the Universe, is still a matter of much debate. Both theoretical models and some recent observations have suggested that mergers do not play a dominant role in the early Universe, but that instead much of the mass growth of galaxies can be attributed to secular processes such as disk instabilities.I will present the results of a detailed, multiwavelength analysis of galaxies selected to have very high star formation rates in the early Universe, at the key epoch when the majority of stars in the Universe formed. By studying the structure and morphology of these objects, we can place constraints on their merger histories and quantify how such an event influences the overall rate of star formation. I will also discuss the relative role that disk instabilities may have had in both star formation and black hole activity.

January 15, 2014

This colloquium will be held at Walter Hall, Room 245, on Wednesday at 4:10 pm