Strong Lensing Legacy Survey
The SL2S survey is a search
dedicated to strong gravitational lenses in the CFHTLS survey.
The CHFTLS has a great potential for strong gravitational
lenses. This deep and accurate survey contains about 1 gravitational
arc per square degree. The CHFTLS
"wide" survey will
cover a surface of about 170 square degrees on the sky, this
survey in the (u*, g',
r', i', z') photometric bands, down to the magnitude i'=24.5. Please
see the CFHTLS
Home
Page for more details.
Ultimately, hundreds of highly
distorded images of distant galaxies
should be identified in the CFHTLS "wide" sky survey. In some
cases the images produced by strong lenses looks like arcs or
arclets
in the images, these images are of particular interest since they
can be identified according to their particular
shape. See
this HST
image of Abell 2218 for a nice illustration. The arcs
are produced when the source is near a caustic which is a singularity
in the mapping introduced by the lens. More information about the
arcs observed in the CFHTLS survey and the SL2S project is
available in the transcript
of the talk given at the CFHTLS users meeting: CFHTLS
meeting presentation . At the present time a total
of about 40 arcs candidates have been found using an automated software
running on sky region 30 square degree ( see astro-ph/0606757
for a description of the method).