Searching for Strong Gravitational Lenses with SNAP
Phil Marshall
KIPAC / Stanford Linear Accelerator Center
pjm@slac.stanford.edu
Additional authors: Roger Blandford
Theoretical predictions and results from previous projects such as CLASS and SDSS suggest a gravitational lensing rate of 1 in 1000 -- combined with the B-band number counts of faint source galaxies from the HDF we might hope to observe a very large number of multiple image systems a wide field optical imaging survey to magnitude 28-30. Basic considerations of lens detection and identification indicate that a survey of the types planned for weak lensing and type 1A Sne with SNAP are close to optimal for the detection of strong lenses. We outline our preliminary expectations for such a "piggy-back'' survey, and sketch out our strategy for detecting and measuring galaxy lenses in the SNAP images. The scientific applications of such a large sample of gravitational lenses are discussed, by no means exhaustively.
