Reionization Lensing Cluster Survey ("RELICS")

RELICS obtained HST infrared imaging of 41 massive galaxy clusters to efficiently search for brightly lensed high-redshift galaxies in time for JWST Cycle 1. The clusters include 21 of the 34 most massive known based on Planck data. Observations of each cluster are split into two epochs, enabling supernova searches in addition to our high-redshift and cluster science. For each cluster, the team observes up to 5-orbit depth with ACS and WFC3/IR. They obtain 3 orbits of ACS imaging in F435W, F606W, and F814W (minus existing archival imaging) and 2 orbits of WFC3/IR imaging in F105W, F125W, F140W, F160W. Five of the clusters require two WFC3/IR pointings. For the 19 clusters with no existing ACS archival imaging, the team also obtains 3-orbit images of blank parallel fields with WFC3/IR F105W, F125W, F140W, F160W (2 orbits) and WFC3/UVIS F350LP (1 orbit) to search for additional high-redshift candidates as in the BoRG and HIPPIES surveys.