RELICS: The Reionization Lensing Cluster Survey and the Brightest High-z Galaxies
Brett Salmon, Dan Coe, Larry Bradley, R. J. Bouwens, Maruša Bradač, Kuang-Han Huang, Pascal A. Oesch, Daniel P. Stark, Keren Sharon, Michele Trenti, Roberto J. Avila, Sara Ogaz, Felipe Andrade-Santos, Daniela Carrasco, Catherine Cerny, William A. Dawson, Brenda Frye, Austin Hoag, Traci L. Johnson, C. Jones, Daniel Lam, L. Lovisari, Ramesh Mainali, Matt Past, Rachel Paterno-Mahler, Avery Peterson, Adam G. Riess, S. Rodney, R. E. Ryan, Irene Sendra-Server, Victoria Strait, Louis-Gregory Strolger, Keiichi Umetsu, Benedetta Vulcani, Adi Zitrin
Abstract
Abstract Massive foreground galaxy clusters magnify and distort the light of objects behind them, permitting a view into both the extremely distant and intrinsically faint galaxy populations. We present here the candidate high-redshift galaxies from the Reionization Lensing Cluster Survey (RELICS), a Hubble and Spitzer Space Telescope survey of 41 massive galaxy clusters spanning an area of ≈200 arcmin 2 . These clusters were selected to be excellent lenses, and we find similar high-redshift sample sizes and magnitude distributions as the Cluster Lensing And Supernova survey with Hubble (CLASH). We discover 257, 57, and eight candidate galaxies at z ∼ 6, 7, and 8 respectively, (322 in total). The observed (lensed) magnitudes of the z ∼ 6 candidates are as bright as AB mag ∼23, making them among the brightest known at these redshifts, comparable with discoveries from much wider, blank-field surveys. RELICS demonstrates the efficiency of using strong gravitational lenses to produce high-redshift samples in the epoch of reionization. These brightly observed galaxies are excellent targets for follow-up study with current and future observatories, including the James Webb Space Telescope .