Fan, XiaohuiXiaohuiFanWang, FeigeFeigeWangYang, JinyiJinyiYangKeeton, Charles R.Charles R.KeetonYue, MinghaoMinghaoYueZabludoff, AnnAnnZabludoffBian, FuyanFuyanBianBONAGLIA, MARCOMARCOBONAGLIAGeorgiev, Iskren Y.Iskren Y.GeorgievHennawi, Joseph F.Joseph F.HennawiLi, JiangtaoJiangtaoLiMcGreer, Ian D.Ian D.McGreerNaidu, RohanRohanNaiduPacucci, FabioFabioPacucciRabien, SebastianSebastianRabienThompson, DavidDavidThompsonVenemans, BramBramVenemansWalter, FabianFabianWalterWang, RanRanWangWu, Xue-BingXue-BingWu2020-12-292020-12-2920192041-8205http://hdl.handle.net/20.500.12386/29307Strong gravitational lensing provides a powerful probe of the physical properties of quasars and their host galaxies. A high fraction of the most luminous high-redshift quasars was predicted to be lensed due to magnification bias. However, no multiple imaged quasar was found at z > 5 in previous surveys. We report the discovery of J043947.08+163415.7, a strongly lensed quasar at z = 6.51, the first such object detected at the epoch of reionization, and the brightest quasar yet known at z > 5. High-resolution Hubble Space Telescope imaging reveals a multiple imaged system with a maximum image separation θ ∼ 0.″2, best explained by a model of three quasar images lensed by a low-luminosity galaxy at z ∼ 0.7, with a magnification factor of ∼50. The existence of this source suggests that a significant population of strongly lensed, high-redshift quasars could have been missed by previous surveys, as standard color selection techniques would fail when the quasar color is contaminated by the lensing galaxy.STAMPAenThe Discovery of a Gravitationally Lensed Quasar at z = 6.51Article10.3847/2041-8213/aaeffe2-s2.0-85060238017000455849600001https://iopscience.iop.org/article/10.3847/2041-8213/aaeffe2019ApJ...870L..11FFIS/05 - ASTRONOMIA E ASTROFISICA