SDSS J090334.92+502819.2: A new gravitational lens

We report the discovery of a new gravitationally lensed quasar from the Sloan Digital Sky Survey, SDSS J090334.92+502819.2. This object was targeted for SDSS spectroscopy as a luminous red galaxy, but manual examination of the spectrum showed the presence of a quasar at zsimilar or equal to3.6 in addition to a red galaxy at z=0.388, and the SDSS image showed a second possible quasar image nearby. Follow-up imaging and spectroscopy confirmed the lensing hypothesis. In images taken at the Astrophysical Research Consortium 3.5 m telescope, two quasars are separated by 2.8; the lensing galaxy is clearly seen and is blended with one of the quasar images. Spectroscopy taken at the Keck II telescope shows that the quasars have identical redshifts of zsimilar or equal to3.6, and both show the presence of the same broad absorption line-like troughs. We present simple lens models that account for the geometry and magnifications. The lens galaxy lies near two groups of galaxies and may be a part of them. The models suggest that the groups may contribute considerable shear that has a strong effect on the lens configuration.