Volume 592, August 2016
|Number of page(s)||21|
|Section||Cosmology (including clusters of galaxies)|
|Published online||28 July 2016|
The PCA Lens-Finder: application to CFHTLS
1 Laboratoire d’Astrophysique, École
Polytechnique Fédérale de Lausanne (EPFL), Observatoire de
Sauverny, 1290 Versoix, Switzerland
2 Department of Astronomy, University of Geneva, Ch. d’Écogia 16, 1290 Versoix, Switzerland
3 Dipartimento di Fisica e Astronomia, Universita di Bologna, via Berti Pichat 6/2, 40127 Bologna, Italy
Accepted: 21 April 2016
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.
Key words: gravitational lensing: strong / galaxies: general / surveys
© ESO, 2016
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.