The CASTLES Imaging Survey of Gravitational Lenses

Session 83 - Gravitational Lensing.
Display session, Friday, January 09
Exhibit Hall,

[83.14] The CASTLES Imaging Survey of Gravitational Lenses

C. Y. Peng (Steward Obs.), E. E. Falco, J. Lehár (CfA), C. D. Impey (Steward Obs.), C. S. Kochanek, B. A. McLeod (CfA), H. -W. Rix (Steward Obs.)

The CASTLES survey (Cfa-Arizona-(H)ST-Lens-Survey) is imaging most known small-separation gravitational lenses (or lens candidates), using the NICMOS camera (mostly H-band) and the WFPC2 (V and I band) on HST. To date nearly half of the IR imaging survey has been completed. The main goals are: to search for lens galaxies where none have been directly detected so far; (2) obtain photometric redshift estimates (VIH) for the lenses where no spectroscopic redshifts exist; (3) study and model the lens galaxies in detail, in part to study the mass distribution within them, in part to identify ``simple" systems that may permit accurate time delay estimates for H_0; (3) measure the M/L evolution of the sample of lens galaxies with look-back time (to z\sim 1); (4) determine directly which fraction of sources are lensed by ellipticals vs. spirals. We will present the survey specifications and the images obtained so far.

Program listing for Friday