Mireia Montes (UNSW)

Mireia Montes Colloquium: Exploring the fossil record of cluster assembly: the intracluster light

Marsfield Lecture Theatre

Abstract

An enigmatic component present in galaxy clusters is the intracluster light (ICL), made up of stars that are not bound to any particular galaxy but drift freely between galaxies in the cluster. Thought to form by the stripping of satellite galaxies as they fall into the cluster, characterizing the ICL is key to understand the assembly mechanisms occurring inside galaxy clusters. Despite its importance, little is known about this light as it is very difficult to observe due to its low surface brightness. In this sense, multi-wavelength deep observations provide valuable information about the progenitors of the ICL.
In this talk, I will present the latest advances in the understanding of the ICL. Using multi-wavelength observations provided by the Hubble Frontier Fields, we have analyzed the ICL of 6 clusters at z~0.4, an interesting time to explore as it is predicted that the ICL forms at z<1. Our results suggest that the ICL of these massive (> 10^15 Msol) clusters is formed by the stripping of MW-like objects that have been accreted at z<1, in agreement with current simulations. Furthermore, we have found that the ICL follows the shape of its underlying dark matter halo, in agreement with the idea that this light is the result of the hierarchical assembly of the cluster.