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


During cosmic reionization, the IGM is heated by ultraviolet photons sourced primarily by the first stars and galaxies. This extreme heating leaves an imprint in the IGM via disrupting the neutral gas with the injection of thermal energy. The thermal relics, i.e. the disruption to the temperature-density evolution of the IGM due to this imprint, has been recently shown to survive to lower redshifts than previously thought (z~2). In this talk, I will demonstrate that these thermal relics depend on the astrophysics of reionization, thus they can, theoretically, be used to distinguish between different reionization histories. In the second part of the talk, I will show how these thermal relics in the Lyman-alpha forest power spectrum — currently a broadband systematic effect for the Lyman-alpha community —could potentially become a novel window into the epoch of reionization.