Map of Σ_* modulated by the ICL, relative to a pivotal value of ∼60 M_⊙/pc². Open black circles indicate the positions of a random realisation of DM sub-haloes, with their location probability following the ICL distribution. The sub-haloes exhibit a mass distribution derived from the small-scale results of N-body simulations of dark matter within galaxy clusters at the MACS 0416 redshift. Larger masses are represented by larger circles. The masses of the sub-haloes that intersect the arc are indicated in the figure. This region shows the central 200 × 200 pixels in Fig. 1.