RELICS: The Reionization Lensing Cluster Survey and the Brightest High-z Galaxies

• Published in: The Astrophysical journal 2020-02, Vol.889 (2), p.189
• Main Authors: Salmon, Brett, Coe, Dan, Bradley, Larry, Bouwens, Rychard, Brada, Marusa, Huang, Kuang-Han, Oesch, Pascal A., Stark, Daniel, Sharon, Keren, Trenti, Michele, Avila, Roberto J., Ogaz, Sara, Andrade-Santos, Felipe, Carrasco, Daniela, Cerny, Catherine, Dawson, William, Frye, Brenda L., Hoag, Austin, Johnson, Traci Lin, Jones, Christine, Lam, Daniel, Lovisari, Lorenzo, Mainali, Ramesh, Past, Matt, Paterno-Mahler, Rachel, Peterson, Avery, Riess, Adam G., Rodney, Steven A., Ryan, Russel E., Sendra-Server, Irene, Strait, Victoria, Strolger, Louis-Gregory, Umetsu, Keiichi, Vulcani, Benedetta, Zitrin, Adi
• Format: Article
• Language: English
• Subjects: ASTRONOMY AND ASTROPHYSICS; Galaxies; galaxies: high-redshift; galaxies: high-redshift — galaxies: evolution — galaxies: clusters: general — galaxies: luminosity function; mass function — gravitational lensing: strong
• ISSN: 0004-637X; 1538-4357; 1538-4357
• DOI: 10.3847/1538-4357/ab5a8b

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 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.