RELICS: Reionization Lensing Cluster Survey
Creators: name: Coe, Dan
name: Salmon, Brett
name: Bradac, Marusa
name: Bradley, Larry D.
name: Sharon, Keren
name: Zitrin, Adi
name: Acebron, Ana
name: Cerny, Catherine
name: Cibirka, Nathalia
name: Strait, Victoria
name: Paterno-Mahler, Rachel
name: Mahler, Guillaume
name: Avila, Roberto J.
name: Ogaz, Sara
name: Huang, Kuang-Han
name: Pelliccia, Debora
name: Stark, Daniel P.
name: Mainali, Ramesh
name: Oesch, Pascal A.
name: Trenti, Michele
name: Carrasco, Daniela
name: Dawson, William A.
name: Rodney, Steven A.
name: Strolger, Louis-Gregory
name: Riess, Adam G.
name: Jones, Christine
name: Frye, Brenda L.
name: Czakon, Nicole G.
name: Umetsu, Keiichi
name: Vulcani, Benedetta
name: Graur, Or
name: Jha, Saurabh W.
name: Graham, Melissa L.
name: Molino, Alberto
name: Nonino, Mario
name: Hjorth, Jens
name: Selsing, Jonatan
name: Christensen, Lise
name: Kikuchihara, Shotaro
name: Ouchi, Masami
name: Oguri, Masamune
name: Welch, Brian
name: Lemaux, Brian C.
name: Andrade-Santos, Felipe
name: Hoag, Austin T.
name: Johnson, Traci L.
name: Peterson, Avery
name: Past, Matthew
name: Fox, Carter
name: Agulli, Irene
name: Livermore, Rachael
name: Ryan, Russell E.
name: Lam, Daniel
name: Sendra-Server, Irene
name: Toft, Sune
name: Lovisari, Lorenzo
name: Su, Yuanyuan
Publisher: name: arXiv
Year: 2019
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences
subject: FOS: Physical sciences

description: Large surveys of galaxy clusters with the Hubble and Spitzer Space Telescopes, including CLASH and the Frontier Fields, have demonstrated the power of strong gravitational lensing to efficiently deliver large samples of high-redshift galaxies. We extend this strategy through a wider, shallower survey named RELICS, the Reionization Lensing Cluster Survey. This survey, described here, was designed primarily to deliver the best and brightest high-redshift candidates from the first billion years after the Big Bang. RELICS observed 41 massive galaxy clusters with Hubble and Spitzer at 0.4-1.7um and 3.0-5.0um, respectively. We selected 21 clusters based on Planck PSZ2 mass estimates and the other 20 based on observed or inferred lensing strength. Our 188-orbit Hubble Treasury Program obtained the first high-resolution near-infrared images of these clusters to efficiently search for lensed high-redshift galaxies. We observed 46 WFC3/IR pointings (~200 arcmin^2) with two orbits divided among four filters (F105W, F125W, F140W, and F160W) and ACS imaging as needed to achieve single-orbit depth in each of three filters (F435W, F606W, and F814W). As previously reported by Salmon et al., we discovered 322 z ~ 6 - 10 candidates, including the brightest known at z ~ 6, and the most distant spatially-resolved lensed arc known at z ~ 10. Spitzer IRAC imaging (945 hours awarded, plus 100 archival) has crucially enabled us to distinguish z ~ 10 candidates from z ~ 2 interlopers. For each cluster, two HST observing epochs were staggered by about a month, enabling us to discover 11 supernovae, including 3 lensed supernovae, which we followed up with 20 orbits from our program. We delivered reduced HST images and catalogs of all clusters to the public via MAST and reduced Spitzer images via IRSA. We have also begun delivering lens models of all clusters, to be completed before the JWST GO call for proposals.
description: 29 pages, 6 figures, submitted to ApJ. For reduced images, catalogs, lens models, and more, see relics.stsci.edu