Exploring the Reionization Epoch with HST and JWST

Abstract

We discuss the detectability of the sources responsible for reionization with existing and planned telescopes. Our approach is based on the number of UV photons required for reionization and depends on relatively few undetermined parameters. We conclude that if the reionization sources are UV-efficient, minimum-luminosity sources, it may be difficult to detect them before the launch of the James Webb Space Telescope. Until then, the best approach may be either to exploit gravitational lensing by clusters of galaxies, or to search for strong Lyα emission by narrow-band imaging or slitless grism spectroscopy.