LAM seminar: Guillaume Mahler – SLICE – Strong LensIng and Cluster Evolution from the largest JWST galaxy cluster survey

Clusters of galaxies are powerful cosmological probes sampling the high-mass end of gravitationally bound systems, providing stringent tests of the structure formation paradigm. A well-understood selection function based on Sunyaev-Zeldovich and X-ray-selected clusters provides an ideal framework for investigating key features of their evolution and the prevalence of self-similarity. Furthermore, the frequency of strong lensing evidence within these structures makes them an ideal target for studying the co-evolution of baryonic and dark matter. The JWST NIRCam program SLICE samples this parameter space over 8 Gyr of cluster formation history (0.2 < z < 1.9), demonstrating the unique ability of deep high-resolution NIR imaging to reveal lensing evidence and cluster-core morphology.

With the first few tens of cluster lens models in hand, I will present an early analysis of these data. I will first show how new lensing constraints contribute to cluster mass modelling, and how the presence of newly discovered dusty lensed galaxies and new substructures in previously recognised lensed background galaxies affects it. In the second part, I will demonstrate how cluster properties evolve over cosmic time — including the dark matter core profile, the morphology of the brightest cluster galaxy, the intra-cluster light distribution, and the globular cluster population.