HEP-Astro Seminar | Probing Cosmological Reionization with the Lyman-alpha Forest

When the first galaxies emerged, ~100 - 500 million years after the Big Bang, their starlight likely reionized and heated the intergalactic hydrogen that had existed since cosmological recombination. Much is currently unknown about this process, including what spatial structure it had, when it started and completed, and even which sources drove it. I will discuss what recent Lyman-alpha forest measurements tell us about the reionization process and about structure formation in the first billion years.