Galaxy Intrinsic Alignments

May 01, 2018 - 12:15 pm to 1:15 pm

Campus, PAB 232

Joe DeRose

The shapes of galaxies provide key insights into the physics of our universe. Astrophysicists have long been interested in measuring the precise shapes of galaxies in order to understand their formation mechanisms. In particular, the correlation of intrinsic galaxy shapes contains interesting information about the relation between galaxy formation and large scale environment, especially as related to the effect of tides on the determination of galaxy properties. More recently, there has been an explosion of interest in measuring galaxy shapes as a probe of gravity and the geometry of the universe via weak gravitational lensing. Here the intrinsic alignment (IA) of galaxy shapes is a nuisance that must be understood in order to precisely measure the global properties of our universe. In this talk I will give an overview of the state of our understanding of galaxy intrinsic alignments. I will begin with a description of contemporary efforts to model galaxy IAs, both analytic and numerical. I will then discuss existing measurements of IAs and their conformation (or lack thereof) to theoretical models, concluding with prospects for the future both in the context of cosmology and galaxy formation.