Search for gravitational lens candidates in the XMM-LSS/CFHTLS common field

TL;DR

This study searches for gravitational lens candidates among optical counterparts of X-ray sources in the XMM-LSS survey, identifying three promising candidates through visual inspection and morphological analysis.

Contribution

It introduces a method combining visual inspection and PSF fitting to identify gravitational lens candidates in a large X-ray survey dataset.

Findings

Identified three strong gravitational lens candidates.

Confirmed candidates are likely QSOs/AGNs based on color and X-ray data.

Reported additional secondary lens candidates.

Abstract

Our aim was to identify gravitational lens candidates among some 5500 optical counterparts of the X-ray point-like sources in the medium-deep ~11 sq. deg. XMM-LSS survey. We have visually inspected the optical counterparts of each QSOs/AGN using CFHTLS T006 images. We have selected compact pairs and groups of sources which could be multiply imaged QSO/AGN. We have measured the colors and characterized the morphological types of the selected sources using the multiple PSF fitting technique. We found three good gravitational lens candidates: J021511.4-034306, J022234.3-031616 and J022607.0-040301 which consist of pairs of point-like sources having similar colors. On the basis of a color-color diagram and X-ray properties we could verify that all these sources are good QSO/AGN candidates rather than stars. Additional secondary gravitational lens candidates are also reported.