Yale Astronomy & Astrophysics Colloquium: “Lyman-alpha galaxies through cosmic time — from reionization to local analogs” Sangeeta Malhotra - Goddard Space Flight Center

Lyman-alpha galaxies are good diagnostics of reionization, but they may also be good sources of hard UV radiation that leads to the ionization of intergalactic gas. The conditions that lead to efficient escape of resonantly scattered Lyman-alpha photons also favor ionizing continuum to escape. Recently we have shown that green-pea galaxies are good low-redshift analogs of high-z Lyman-alpha galaxies. Using these we can start to understand Lyman-alpha emitters in great detail. What is different about these galaxies? What makes Lyman-alpha escape? By understanding the Lyman-alpha escape from galaxies at lower redshifts we fine-tune them to diagnose the neutral fraction of the intergalactic gas at the epoch of reionization.