The Search for Inverse Compton Scattering in Merging Galaxy Clusters

Since the first non-thermal reports of inverse Compton (IC) emission from the intracluster medium (ICM) of galaxy clusters at hard X-ray energies, we have yet to unambiguously confirm IC emission in observations with newer facilities. Observatories like RXTE and BeppoSAX have detected IC emission in clusters like Abell 2163 and the Coma Cluster, while later observations done with Suzaku and XMM-Newton have just resulted in upper limits. NuSTAR, one of the latest X-ray observatories to launch, will help deal with this ambiguity using its ability to probe the higher energy bands where IC emission is normally found and where other telescopes fall short. In this talk we will present the results of four merging clusters: Abell 2163, Abell 665, Abell 2146, and MACSJ0717. To determine the global diffuse IC emission, we use different models to characterize both thermal and non-thermal ICM emission. In all four cases we find no significant presence of IC emission and set upper limits for the emission flux. Using the emission flux along with VLA and LOFAR data, we are able to provide strong constraints on the lower limits for the magnetic fields of the clusters.