Description
The self-interacting dark matter (SIDM) model has garnered increasing attention as a potential solution to discrepancies between dark matter-only simulations and observations in small scales. SIDM predicts distinct tidal interaction histories compared to the cold dark matter (CDM) model, leading to differences in the evolution and distribution of intracluster light (ICL). In this study, we analyze galaxy clusters from the Cluster-EAGLE (C-EAGLE) zoom-in cosmological simulation, including two clusters re-simulated under identical initial conditions within a SIDM universe. Our findings indicate that dark matter is traced with the highest accuracy in the following order: brightest cluster galaxy (BCG) + ICL > gas > all stars > galaxies. Over time, the tracing performance improves for BCG+ICL and gas, whereas it declines for all stars and galaxies. BCG+ICL consistently serves as a reliable tracer, even at high redshift, while gas initially performs poorly but gradually improves, eventually becoming comparable to BCG+ICL. In the SIDM case, the gas distribution more closely resembles dark matter than in the CDM case. This suggests that in CDM, dark matter remains collisionless and behaves similarly to BCG+ICL, whereas, in SIDM, it exhibits mild viscosity and behaves more like gas. This study serves as an exploratory analysis to assess the potential of using ICL as a probe for constraining dark matter models.
