Searching for Dust in the Intracluster Medium from Reddening of Background Galaxies

We report a search for the presence of dust in the intracluster medium based on the study of statistical reddening of background galaxies. Armed with the Red-sequence Cluster Survey data, from which we extracted (1) a catalog of 458 clusters with z clust < 0.5 and (2) a catalog of ~90,000 galaxies with photometric redshift 0.5 < z ph < 0.8 and photometric redshift uncertainty δ z ph /(1 + z ph ) < 0.06, we have constructed several samples of galaxies according to their projected distances to the cluster centers. No significant color differences [⟨ E(B − R C ) ⟩ = 0.005 ± 0.008 and ⟨ E(V − z ' ) ⟩ = 0.000 ± 0.008] were found for galaxies in the background to the clusters compared to the references. Assuming a Galactic extinction law, we derive an average visual extinction of ⟨ A V ⟩ = 0.004 ± 0.010 toward the inner R 200 of clusters.