Multi-color image of the center of the cluster Abell 2163 with overlays of the dark matter distribution (green contours from the lensing map) and of the gas distribution (red contours for the Chandra X-rays image, courtesy Bourdin). The shift between the two mass clumps is 3′, while the distance between the X-ray maximum and the eastern clump A2163-A1 is 1.2′. The total size is 10′ ×  10′.