Lyman-alpha forest power spectrum as an emerging window into the epoch of reionization and cosmic dawn


The memory of reionization in the Lya forest was recently shown to survive to lower redshifts than previously thought (z~2). This unconventional result originated from carefully tracking the small-scale structure to below jean mass prior to reionization with high-resolution simulations. As a result, one is able to track the HEMD (High-Entropy, Mean-Density) gas in mini-voids, which takes cosmological timescales to relax into the usual-temperature density relation of the IGM. Here, I will show how the memory of inhomogeneous reionization in the Lya forest power spectra — currently a broadband systematic effect for the Lya forest community- could potentially become a window into the Epoch of Reionization.