The intra-cluster light as estimator of the cluster's mass profile (2507.05404v1)

Abstract: Context. The intra-cluster light (ICL) comprises stars that are unbound to individual galaxies within a galaxy cluster and provides insights into the cluster's mass distribution, evolutionary history and dynamical state. Aims. We aim to study the viability of the intra-cluster stellar mass as a proxy to compute the total mass profiles of galaxy clusters. Methods. High-resolution simulations from the C-EAGLE project are used to study the ratio between intra-cluster stellar mass and total matter projected densities. This ratio follows a power-law, and a model is presented for its fit parameters and associated errors. Results. The aforementioned relation is used to estimate the mass profile of the Perseus cluster using Euclid observations that extend up to 1/3 of the virial radius. The obtained cluster mass is compatible with other measurements from galaxy velocity dispersion, though it is overestimated by a factor 2 compared to X-ray mass estimates. We repeat this process for four clusters in the Hubble Frontier Fields, finding compatibility with weak and strong lensing mass estimates. Conclusions. This methodology provides an independent approach to cluster mass estimation based solely on observed ICL and a simulation-calibrated relation.