Abstract

Characterizing galaxies <1 Gyr after the Big Bang is crucial for constraining the main sources of reionization, the last major phase change of the Universe from a neutral to ionized intergalactic medium (IGM). We present the Web Epoch of Reionization Lyman-alpha Survey (WERLS), a 29-night NASA key strategic mission support program using Keck/MOSFIRE+LRIS to conduct a spectroscopic redshift survey of Lyman-alpha emission from ~800 already identified UV-bright galaxies embedded in the Epoch of Reionization (EoR). Here, I discuss early results from WERLS targets detected with MOSFIRE at z~7-8, and synergy with Cycle 1/ERS JWST NIRCam imaging. WERLS is designed to be a pre-follow-up survey for the first large extragalactic imaging surveys from JWST over 0.7deg^2: COSMOS-Web, PRIMER-UDS, and CEERS. These programs have already resulted in detections and new discoveries of galaxies in the EoR, and will allow us to map the galaxy distribution in large scale structure on 10-100 Mpc scales. With WERLS, we will directly compare the Lyman-alpha-inferred location of ionization bubbles to underlying galaxy density maps measured via deep NIRCam imaging to constrain the galaxies responsible for reionization and map ionized bubbles in the IGM on large scales.