Subaru Weak Lensing Study of Seven Merging Clusters: Distributions of Mass and Baryons

We present and compare projected distributions of mass, galaxies, and theintracluster medium (ICM) for a sample of merging clusters of galaxies based onthe joint weak-lensing, optical photometric, and X-ray analysis. Our samplecomprises seven nearby Abell clusters, for which we have conducted systematic,deep imaging observations with Suprime-Cam on Subaru telescope. Our seventarget clusters, representing various merging stages and conditions, allow usto investigate in details the physical interplay between dark matter, ICM, andgalaxies associated with cluster formation and evolution. A1750 and A1758 arebinary systems consisting of two cluster-sized components, A520, A754, A1758N,A1758S, and A1914 are on-going cluster mergers, and A2034 and A2142 arecold-front clusters. In the binary clusters, the projected mass, optical light,and X-ray distributions are overall similar and regular without significantsubstructures. On-going and cold-front merging clusters, on the other hand,reveal highly irregular mass distributions. Overall the mass distributionappears to be similar to the galaxy luminosity distribution, whereas theirdistributions are quite different from the ICM distribution in a various ways.We also measured for individual targets the global cluster parameters such asthe cluster mass,the mass-to-light ratio, and the ICM temperature. A comparisonof the ICM and virial temperatures of merging clusters from X-ray andweak-lensing analyses, respectively, shows that the ICM temperature of on-goingand cold-front clusters is significantly higher than the cluster virialtemperature by a factor of $\sim 2$. This temperature excess in the ICM couldbe explained by the effects of merger boosts.