Astrophysics Observations of the first light and the epoch of reionization

Abstract Studying the first generation of stars, galaxies and supermassive black holes as well as the epoch of reionization is one of the fundamental questions of modern as-trophysics. The last few years have witnessed the first confirmation of the discoveries of galaxies, quasars and Gamma-Ray Bursts at z> 7, with possible detections at z ∼ 10. There is also mounting evidence that cosmic reionization is a prolonged pro-cess that peaks around z ∼ 10 and ends at z ∼ 6 − 7. Observations of the highest redshift intergalactic medium and the most metal-poor stars in the Galaxy begin to constrain the earliest chemical enrichment processes in the Universe. These observa-tions provide a glimpse of cosmic history over the first billion years after the Big Bang. In this review, we will present recent results on the observations of the high-redshift Universe over the past decade, highlight key challenges and uncertainties in these ob-servations, and preview what is possible with the next generation facilities in studying the first light and mapping the history of reionization