# SDSSJ102111.02+491330.4: A Newly Discovered Gravitationally Lensed Quasar

Research paper by Bart Pindor, Daniel J. Eisenstein, Michael D. Gregg, Robert H. Becker, Naohisa Inada, Masamune Oguri, Patrick B. Hall, David E. Johnston, Gordon T. Richards, Donald P. Schneider, Edwin L. Turner, Guido Brasi, Philip M. Hinz, Matthew A. Kenworthy, Doug Miller, et al.

Indexed on: 12 Sep '05Published on: 12 Sep '05Published in: Astrophysics

#### Abstract

We report follow-up observations of two gravitational lens candidates identified in the Sloan Digital Sky Survey (SDSS) dataset. We have confirmed that SDSS J102111.02+491330.4 is a previously unknown gravitationally lensed quasar. This lens system exhibits two images of a $z = 1.72$ quasar, with an image separation of $1{\farcs}14 \pm 0.04$. Optical and near-IR imaging of the system reveals the presence of the lensing galaxy between the two quasar images. Observations of SDSS J112012.12+671116.0 indicate that it is more likely a binary quasar than a gravitational lens. This system has two quasars at a redshift of $z = 1.49$, with an angular separation of $1{\farcs}49 \pm 0.02$. However, the two quasars have markedly different SEDs and no lens galaxy is apparent in optical and near-IR images of this system. We also present a list of 31 SDSS lens candidates which follow-up observations have confirmed are \textit{not} gravitational lenses.