Citation:
Date Published:
November 1, 2005Abstract:
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.