X-ray images extracted from two alternative simulations of the merger models DBf_rc20 (Fig. 10) and XDBf_sb (Fig. 12). The only difference in the simulation setup is the initial value of the SE cluster halo concentration parameter, . From Eq. (5) the concentration parameter of these models is fixed to , while for this study we set here (left panels) and (right panels). Top panels are for model DBf_rc20 and bottom panels for model XDBf_sb. A negative d_X-DM offset indicates that the X-ray peak is trailing the DM centroid of the SE cluster.