摘要：We present the results of a new search for galaxy-scale strong lensing systems in CFHTLS
Wide. Our lens-finding technique involves a preselection of potential lens galaxies,
applying simple cuts in size and magnitude. We then perform a Principal Component Analysis
of the galaxy images, ensuring a clean removal of the light profile. Lensed features are
searched for in the residual images using the clustering topometric algorithm DBSCAN. We
find 1098 lens candidates that we inspect visually, leading to a cleaned sample of 109 new
lens candidates. Using realistic image simulations we estimate the completeness of our
sample and show that it is independent of source surface brightness, Einstein ring size
(image separation) or lens redshift. We compare the properties of our sample to previous
lens searches in CFHTLS. Including the present search, the total number of lenses found in
CFHTLS amounts to 678, which corresponds to ∼4 lenses per square degree down to i(AB) =
24.8. This is equivalent to ∼60.000 lenses in total in a survey as wide as Euclid, but at the
CFHTLS resolution and depth.
