AAS 203rd Meeting, January 2004
Session 120 Gravitational Lensing
Poster, Thursday, January 8, 2004, 9:20am-4:00pm, Hanover Hall

## [120.10] The Most Widely Separated Lensed QSO

A.R. Marble, C.D. Impey, K.A. Eriksen, L. Bai (University of Arizona), L. Miller (Oxford)

We present optical spectroscopy of the QSO pair 2QZ J1435+0008. Discovered in the 2dF QSO Survey, this pair has a redshift of z = 2.378 and an angular separation of 33\arcsec. Data taken with the MMT show that the spectra of the two QSOs are very similar over the region between Lyman-\alpha and C~IV emission, consistent with a lensing interpretation. An analysis of the Lyman-\alpha forest blueward of the emission redshift provides even stronger support for the lens hypothesis. The almost perfect correlation between the HI absorption along the two sightlines is consistent with converging sightlines that traverse the IGM on sub-galaxy scales, but is inconsistent with being binary QSOs, where the diverging sightlines would span a comoving transverse scale of ~1 Mpc. 2QZ J1435+0008 thus appears to be a gravitational lens, with by far the widest angular separation among the ~80 known examples of QSOs with multiple image formation.

Bulletin of the American Astronomical Society, 35#5
© 2003. The American Astronomical Soceity.