Understanding the Epoch of Cosmic Reionization / Astrophysics and Space Science Library Bd.423 (PDF)

present-day one. It is fundamental in understanding cosmic origins, and its impact on structure formation resonates even to this day. Until recently, there was very little observational insight into the epoch of reionization. Subsequent observational and theoretical advancements have begun to paint a picture of a complicated, extended, inhomogeneous process. At its core, the process of cosmological reionization involves understanding how stars and clumps of gas impact each other and eventually the entire Universe. The challenges associated with such an enormous range of relevant scales, coupled with our relatively poor understanding of the dominant astrophysics, have thus far impeded efforts to form a solid theoretical framework. As such, the interpretation of the reionization data currently available remains controversial even as the wealth of data is increasing thanks to more sophisticated analytical and numerical approaches. Investigations have become subtler, discarding the "one size fits all" approach in favor of focused studies with specialized tools, placing astrophysics on the cusp of a dramatic increase in knowledge. What is the best use of limited observational resources? How to develop theoretical tools tailored for each observation? Ultimately, what will be learned about the epoch of reionization and the Universe's galactic ancestors?