Discovery of a Quadruple Lens in CANDELS with a Record Lens Redshift z = 1.53
Ferguson, H. C.; Finkelstein, S. L.; Rudnick, G. H.; Koekemoer, A. M.; Grazian, A.; Faber, S. M.; van der Wel, A.; Koo, D. C.; Grogin, N. A.; Kocevski, D. D.; Rix, H. W.; Maseda, M.; van de Ven, G.
Germany, United States, Italy
Abstract
Using spectroscopy from the Large Binocular Telescope and imaging from the Hubble Space Telescope we discovered the first strong galaxy lens at z lens > 1. The lens has a secure photometric redshift of z = 1.53 ± 0.09 and the source is spectroscopically confirmed at z = 3.417. The Einstein radius (0.''35; 3.0 kpc) encloses 7.6 × 1010 M ⊙, with an upper limit on the dark matter fraction of 60%. The highly magnified (40×) source galaxy has a very small stellar mass (~108 M ⊙) and shows an extremely strong [O III]5007 Å emission line (EW0 ~ 1000 Å) bolstering the evidence that intense starbursts among very low-mass galaxies are common at high redshift.