Tracing the mass distribution and assembly of galaxy clusters with ICL and dynamical indicatorsConfirmed

by Syeda Lammim Ahad (Waterloo Centre for Astrophysics)

Tuesday Feb 3, 2026, 11:00 AM → 12:30 PM America/Toronto

PI/4-405 - Bob Room (Perimeter Institute for Theoretical Physics)

Galaxy clusters assemble hierarchically, and their present-day dynamical state encodes information about cluster formation timescales and mass distribution. The diffuse intracluster light (ICL), a fossil record of tidal stripping and accretion, offers a complementary probe that is sensitive to a cluster’s assembly history. In this talk I will present recent works based on photometric surveys (Euclid, UNIONS, DESI Legacy, KiDS) and cosmological hydrodynamic simulations (e.g. IllustrisTNG, Hydrangea), addressing two questions: (i) how observational tracers (e.g. magnitude gaps, galaxy-stellar-mass ratios) can be used to identify cluster dynamical state and its imprint on cluster properties; and (ii) what the ICL fraction and morphology reveal about the underlying mass and the stage of assembly. If time allows, I will briefly describe ongoing work with the FLAMINGO simulations that connects high-redshift protoclusters to their descendant clusters using observational indicators of environment and assembly.