Abstract

Determining the contribution of galaxies to the reionization of the universe is a fundamental goal for studies of the intergalactic medium (IGM), and galaxy formation and evolution. A direct measurement of ionizing Lyman-continuum radiation escaping from galaxies is not possible at the epoch of reionization, due to the high optical depth of the IGM. Therefore, observations of this process at lower redshift are crucial for understanding what happens at z>6. There has been much recent progress in measuring the escape fraction of ionizing radiation in both nearby and distant star-forming galaxies. The current challenge is to use these new observations to predict the contribution of star-forming galaxies to the ionizing background during the epoch of reionization.