  The bulk of stars in galaxy clusters are confined within their constituent
galaxies. Those stars do not trace the extended distribution of dark matter
well as they are located in the central regions of the cluster's dark matter
sub-halos. A small fraction of stars is expected, however, to follow the global
dark matter shape of the cluster. These are the stars whose extended spatial
distribution results from the merging activity of galaxies and form the
intracluster light (ICL). In this work, we compare the bi-dimensional
distribution of dark matter in massive galaxy clusters (as traced by
gravitational lensing models) with the distribution of the ICL. To do that, we
use the superb data from the Hubble Frontier Fields Initiative. Using the
Modified Hausdorff distance (MHD) as a way of quantifying the similarities
between the mass and ICL distributions, we find an excellent agreement (MHD~25
kpc) between the two components. This result shows that the ICL exquisitely
follows the global dark matter distribution, providing an accurate luminous
tracer of dark matter. This finding opens up the possibility of exploring the
distribution of dark matter in galaxy clusters in detail using only deep
imaging observations.
