Contours of the extended X-ray emission overlaid on the CFHTLS RGB image in i′, r′, g′ filters. Top left panel shows a spectroscopically confirmed cluster at z = 0.47 within the center of X-ray emission and having a single optical counterpart, with a high significance of X-ray flux estimate (flag = 1 and flag = 3 if without the spectroscopic confirmation). Top right panel, assigned with a flag = 2, indicates a presence of two overlapping X-ray sources at z = 0.52 and z = 0.15. The bottom left image shows the multiple optical counterparts within the X-ray emission with no possibility of separating out their contributions (flag = 4). The bottom right panel shows a galaxy group at z = 0.60 located at the edge of X-ray emission (flag = 5). The scale bar is presented in each image.