Abstract:
ABSTRACT DIFFUSE LIGHT IN GALAXY CLUSTERS ON DARK ENERGY SURVEY AND ITS CONNECTION WITH THEIR MASS We explore the relation between diffuse intracluster light (central galaxy included) and galaxy cluster mass using a sample of 528 clusters at redshift range 0.2 <= z <= 0.35 from the Dark Energy Survey (DES) Year 1 data. The diffuse light surface brightness profile shows an increasing dependence with cluster total mass and appears to be self-similar. We also compare the diffuse light radial profiles and the cluster (baryonic and dark) matter distribution measured through weak gravitational lensing and we find them to be comparable, as well as the radial distribution of the cluster total light (diffuse light + satellites). We use the IllustrisTNG simulation to explore the connection between diffuse stellar mass and cluster matter distributions -- the simulation radial profile of the diffuse stellar component does not have a similar slope with the total cluster matter content, although that of the cluster satellite galaxies does. Nevertheless, the amount of diffuse stellar mass has a low-scatter scaling relation with cluster's total mass in the simulation, out-performing the total stellar mass of cluster satellite galaxies. Thus, we conclude that there is no convincing evidence on whether or not diffuse light is a good radial tracer of the cluster matter distribution. Still, both observations and simulations show that diffuse light is an excellent proxy of total mass in clusters.
