Deep infrared images from the Hubble and Spitzer Space Telescopes have recently pushed the cosmic frontier back to just 500 million years after the Big Bang, delivering the first reliable census of galaxies in what is likely the heart of the reionization era. I will discuss implications of these results for the growth of early galaxies and their contribution to reionization. I will then present the latest results of a large ground-based spectroscopic program aimed at using these new samples of galaxies as probes of the ionization state of the IGM at z>7. Finally, I will discuss how spectroscopic study of low metallicity gravitationally-lensed galaxies is providing insight into the likely escape fraction and ionizing output of galaxies in the reionization era while simultaneously helping to define a new approach to studying galaxies at z>7.
University of Arizona