Stacked F814W HST ACS second residual images of all ten considered clusters (upper figure), of the z ≤ 0.65 clusters (middle figure: 5 clusters taken into account), and of the z ≥ 0.70 clusters (lower figure: 5 clusters taken into account). Images are 200 × 200 kpc² wide. The upper figure also shows as red circles the positions of the brightest cluster galaxies of the stacked clusters.