SDSS J024634.11-082536.2: A New Gravitationally Lensed Quasar from the Sloan Digital Sky Survey


Inada N, Burles S, Gregg MD, Becker RH, Schechter PL, Eisenstein DJ, Oguri M, Castander FJ, Hall PB, Johnston DE, et al. SDSS J024634.11-082536.2: A New Gravitationally Lensed Quasar from the Sloan Digital Sky Survey. The Astronomical Journal. 2005;130 :1967-1976.

Date Published:

November 1, 2005


We report the discovery of a new two-image gravitationally lensedquasar, SDSS J024634.11-082536.2 (SDSS J0246-0825). This object wasselected as a lensed quasar candidate from the Sloan Digital Sky Survey(SDSS) by the same algorithm that was used to discover other SDSS lensedquasars (e.g., SDSS J0924+0219). Multicolor imaging with the MagellanConsortium's Walter Baade 6.5 m telescope and spectroscopic observationsusing the W. M. Keck Observatory's Keck II telescope confirm that SDSSJ0246-0825 consists of two lensed images (Δθ=1.04") of asource quasar at z=1.68. Imaging observations with the Keck I telescopeand the Hubble Space Telescope reveal an extended object between the twoquasar components, which is likely to be a lensing galaxy of thissystem. From the absorption lines in the spectra of the quasarcomponents and the apparent magnitude of the galaxy, combined with theexpected absolute magnitude from the Faber-Jackson relation, we estimatethe redshift of the lensing galaxy to be z=0.724. A highly distortedring is visible in the Hubble Space Telescope images, which is likely tobe the lensed host galaxy of the source quasar. Simple mass modelingpredicts the possibility that there is a small (faint) lensing objectnear the primary lensing galaxy.Based on observations with the NASA/ESA Hubble Space Telescope, obtainedat the Space Telescope Science Institute, which is operated by theAssociation of Universities for Research in Astronomy (AURA), Inc.,under NASA contract NAS5-26555. These observations are associated withHST program 9744.