The reionization of hydrogen in the intergalactic medium (IGM) was a landmark in structure formation. (Re ionization, since the Universe was also ionized during the brief time after the Big Bang before there were any atoms). It was the first time that stars had a global impact on the universe, and the last time that most of the ordinary matter in the universe participated in a phase transition. With Cosmic Dawn we refer to this important epoch of transition.

Our team aims to characterize the epoch, speed, and inhomogeneity of cosmic reionization, as well as the sources responsible for reionization.