Description
Galaxy clusters form through hierarchical merging, with the intracluster light (ICL) serving as a luminous tracer of these processes. The distribution and morphology of ICL provide critical insights into the evolution of galaxy clusters. Moreover, the stripped stars that form the ICL are bound to underlying gravitational potential of the cluster, thus making the ICL a valuable probe for the dark matter distribution. Additionally, the shape and radial extent of ICL can be used to study a cluster’s dynamical state, helping to determine whether it is relaxed or merging. However, the faint nature of ICL poses significant challenges for studying its characteristics. With the advent of high-resolution data from Euclid, we can now study the ICL's shape and extent with unprecedented depth. Using data from the Euclid Q1 release, we present a pilot study of the ICL shapes (e.g., ellipticity, position angle and lopsidedness) across multiple wavelengths in ~20 massive eRosita galaxy clusters. We assess which Euclid filter—VIS, H, J, or Y—is the most effective for measuring the ICL’s shape and radial extent, and investigate the link between ICL morphology and the dynamical state of the clusters. Additionally, we highlight the need for optimised data processing techniques tailored to the low surface brightness regime, which are essential for accurately constraining the ICL’s properties and deepening our understanding of galaxy cluster evolution. This work lays the foundation for extending the analysis to the upcoming Euclid DR1 which will offer a larger statistical sample for more robust investigations.
