AAS 197, January 2001
Session 105. Gravitational Lensing
Display, Thursday, January 11, 2001, 9:30-4:00pm, Exhibit Hall

## [105.06] {\em Chandra} Imaging of the Wide Separation Quasar Pair 2345+007

P. J. Green (SAO), A. Siemiginowska (SAO), M. Markevitch (SAO), C. Kochanek (SAO), J. Silverman (SAO)

We have imaged with {\em Chandra} the wide (7\prime\prime) separation quasar pair Q2345+007 to determine whether it is a binary quasar or a gravitational lens and to probe the nature of the lensing matter. With nearly identical optical spectra and identical redshifts, this quasar pair remains the most intriguing example of an observed configuration which seems to require the presence of massive, concentrated dark matter acting as a gravitational lens. We present an analysis of the quasars X-ray properties and describe results of our tests for extended emission both centered on the quasar pair, and at the positions of mass concentrations suggested from optical galaxy counts.