RELICS: The Reionization Lensing Cluster Survey and the Brightest High-z Galaxies
Frye, Brenda L.; Strait, Victoria; Lovisari, Lorenzo; Riess, Adam G.; Zitrin, Adi; Coe, Dan; Andrade-Santos, Felipe; Salmon, Brett; Sharon, Keren; Trenti, Michele; Umetsu, Keiichi; Bradley, Larry; Carrasco, Daniela; Cerny, Catherine; Huang, Kuang-Han; Jones, Christine; Lam, Daniel; Mainali, Ramesh; Oesch, Pascal A.; Ogaz, Sara; Paterno-Mahler, Rachel; Peterson, Avery; Sendra-Server, Irene; Vulcani, Benedetta; Bouwens, Rychard; Hoag, Austin; Strolger, Louis-Gregory; Rodney, Steven A.; Avila, Roberto J.; Stark, Daniel; Dawson, William; Bradač, Marusa; Johnson, Traci Lin; Past, Matt; Ryan, Russel E.
United States, Netherlands, Switzerland, Australia, Taiwan, Italy, Israel
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 $z\sim 6\mbox{--}8$ 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 arcmin2. 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.