Intracluster light (ICL) is the diffuse stellar light stripped from galaxies within a galaxy cluster. It is collisionless and is bound to the gravitational potential of a cluster. Stars in halo are accreted through mergers, and may follow same assembly process as the dark matter, and so may have the same distribution.
Thus, ICL can be used as a tracer of the dark matter haloes in clusters!
Currently in the University of Nottingham, I work on studying the shape of ICL, which can orobe to the shape of dark matter haloes in galaxy clusters. Such study can then help us gain insights into the nature of dark matter, whteher it is self interacting or not!
In Nottingham, we have one of the largest group focusing many different aspects of the ICL science. We use observations from cutting edge data of various instruments -- like Euclid Space Telescope and MUSE IFU, and/or using state of the art hydrodynamical simulations like Hydrangea and TNG!
Perseus Cluster observed by Euclid Space Telescope.
Credits: ESA/Euclid/Euclid Consortium/NASA, image processing by J.-C. Cuillandre (CEA Paris-Saclay), G. Anselmi.