Spatially Variable Light and Environments in a Distant Galaxy

Abstract

By Riley Owens, Astrophysics and Physics

Advisor: Matthew Bayliss

Presentation ID: 22

Abstract: Following the Big Bang, our universe cooled enough to allow free protons and electrons to recombine into neutral matter. The first generation of stars and galaxies reionized this matter, but how exactly this happened remains poorly understood. In the local universe, insufficient ionizing radiation escapes galaxies to explain the amount of ionized matter observed. In light of this, we study a unique, especially bright galaxy which is known to leak significant amounts of ionizing radiation. Using observations of the UV light escaping the galaxy, we characterize its physical environments. Strong magnification of the galaxy allows us to distinguish physically distinct regions, across which we see significant spatial variations. These indicate large changes in the properties of gas along different lines of sight into the galaxy. The extreme ionizing radiation the galaxy emits is a property associated with the galaxies responsible for reionizing the universe. So, though the process of reionization predates the galaxy's age, this is suggestive that highly anisotropic gas in the first generation of galaxies is likely an important factor in explaining how the universe reionized.