Event Details

Dr. Alexandra Le Reste, Postdoctoral Research Associate, School of Physics and Astronomy University of Minnesota, will present " What nearby galaxies teach us about the beginning of the Universe."

The Universe changed drastically during its first billion year as neutral hydrogen gas, which filled the intergalactic space, became ionized. This last major phase transition of the Universe is an important cosmological period known as the Epoch of Reionization. Simulations and new observations using powerful telescopes indicate that primordial galaxies were the main sources of the ionizing UV photons responsible for Reionization. However, many unknowns remain on the mechanisms that enabled these photons to escape the neutral interstellar medium of galaxies to ionize the space around them on much larger scales. Here, I will show how we can use observations of nearby galaxies to understand the physical processes that caused cosmological reionization. In particular, we will see what observations of the neutral gas reservoirs of rare local galaxies analogous to objects in the early universe teach us about the potential role of galaxy interactions during the Epoch of Reionization.

Refreshments at 3 p.m.