The Epoch of Reionization constitutes the last major phase transition of our universe. During this early evolutionary phase, the cosmic “dark ages” following recombination ended and the intergalactic gas transitioned from a neutral state into the ionized medium that we observe today due to the ionizing radiation of the first luminous objects - the first stars, galaxies, and quasars. Understanding the details of this reionization era constrains the nature of these primordial objects and the formation of large scale structure, and is therefore one of the major goals of observational cosmology today. Our new measurements of the evolution of the opacity of the intergalactic medium along high-redshift quasar sightlines within the Lyman-alpha forest as well as the Lyman-beta forest shed new light on the timing and morphology of the reionization epoch.
The Epoch of Reionization constitutes the last major phase transition of our universe. During this early evolutionary phase, the cosmic “dark ages” following recombination ended and the intergalactic gas transitioned from a neutral state into the ionized medium that we observe today due to the ionizing radiation of the first luminous objects - the first stars, galaxies, and quasars. Understanding the details of this reionization era constrains the nature of these primordial objects and the formation of large scale structure, and is therefore one of the major goals of observational cosmology today. Our new measurements of the evolution of the opacity of the intergalactic medium along high-redshift quasar sightlines within the Lyman-alpha forest as well as the Lyman-beta forest shed new light on the timing and morphology of the reionization epoch.