Cluster members of MACS 1206 used in the strong lensing models. Galaxies that do not satisfy the selection criteria described in Sect. 3.2.1 have been masked out of the original HST image using the SExtractor segmentation map. The white lines show the contour levels of the reconstructed surface mass density of the diffuse mass components only (obtained by removing the surface mass density of the cluster member halos from that of the total), corresponding to the values of [1.0,1.5,2.0,3.0] × 10¹⁵M_⊙ Mpc^-2. The magenta lines show the isocontours of the 0.5−7 keV Chandra X-ray detection. The green crosses indicate the positions of the multiple images shown with white and green circles in Fig. 1.