Discovery of a Very Bright and Intrinsically Very Luminous, Strongly Lensed Lyα Emitting Galaxy at z = 2.82 in the BOSS Emission-Line Lens Survey
Brownstein, Joel R.; Marques-Chaves, Rui; Oguri, Masamune; Kochanek, Christopher S.; Mao, Shude; Bolton, Adam S.; Shu, Yiping; Zheng, Zheng; Pérez-Fournon, Ismael; Cornachione, Matthew A.; Montero-Dorta, Antonio D.; Martínez-Navajas, Paloma I.
Spain, China, United States, Japan, United Kingdom
Abstract
We report the discovery of a very bright (r = 20.16), highly magnified, and yet intrinsically very luminous Lyα emitter (LAE) at z=2.82. This system comprises four images in the observer plane with a maximum separation of ∼ 6\prime\prime and it is lensed by a z=0.55 massive early-type galaxy. It was initially identified in the Baryon Oscillation Spectroscopic Survey Emission-Line Lens Survey for GALaxy-Lyα EmitteR sYstems survey, and follow-up imaging and spectroscopic observations using the Gran Telescopio Canarias and William Herschel Telescope confirmed the lensing nature of this system. A lens model using a singular isothermal ellipsoid in an external shear field reproduces the main features of the system quite well, yielding an Einstein radius of 2.″95 ± 0.″10, and a total magnification factor for the LAE of 8.8 ± 0.4. This LAE is one of the brightest and most luminous galaxy-galaxy strong lenses known. We present initial imaging and spectroscopy showing the basic physical and morphological properties of this lensed system.
Based on observations made with the Gran Telescopio Canarias (GTC) and William Herschel Telescope (WHT), in the Spanish Observatorio del Roque de los Muchachos of the IAC, under Directors Discretionary Time (DDT programs IDs: GTC2016-054 and DDT2016-077).