Shocked Electrons: Determination of the Heating Mechanism in Abell 665*

Mergers between galaxy clusters drive shock fronts in the intracluster medium (ICM), heating thermal electrons, causing an increase in their temperature. The mechanism by which this occurs is undetermined, with two models being proposed to explain the phenomenon. One proposes direct shock-heating and the other suggests indirect adiabatic compression with subsequent ion-equilibration. We utilize NuSTAR observations of a shock in the merging cluster Abell 665 in order to discriminate between the models. A temperature profile was constructed across the shock in order to compare against the models' predictions. In addition, temperature maps across the cluster are generated in order to understand merger activity. We find that the temperature profile is suggestive of the shock model but is not statistically significant, due to NuSTAR's comparatively worse spatial resolution. Current work is joint fitting the NuSTAR data with Chandra observations in order to statistically distinguish between the models for the first time. Understanding these processes increases our understanding of the magnetic field of the ICM, allowing galaxy clusters to be used to constrain cosmology.