Do electrons ghost Ions after a merger? - a NuSTAR investigation of intracluster plasma in Abell 2146

Galaxy clusters are the most massive gravitationally bound objects in the universe. Cluster mergers convert upwards of 1065 ergs of gravitational potential energy into the kinetic energy of the intracluster medium (ICM), the hot ionized plasma between galaxies in a cluster (Zuhone & Su 2022). Merger features in the ICM help constrain plasma physics parameters such as electron-ion thermal equilibration timescales (eiTETs) across shock fronts between equilibration in a matter of seconds (instant model) and equilibration over tens of millions of years (collisional model). This poster shares results of processing a ~260 kilo-second NuSTAR observation of the galaxy cluster merger Abell 2146 and report best fits of the post-shock temperatures and the eiTETs in the two ~10 keV shock fronts the cluster possesses. So far, constraints on eiTETs in cluster mergers have shown a mixed bag of results potentially due of Chandra X-ray telescope's over-estimation of temperatures beyond its upper limit of 10 keV (Wallbank 2022). This makes using NuSTAR's hard X-ray imaging capabilities on the Chandra - studied Abell 2146 an important calibration experiment. Abell 2146 Gravitational Potential energy Kinetic energy Thermal en-ergy Thermalization.