Measuring sloshing comma merging and feedback velocities in Centaurus and Virgo

Despite its importance for understanding cluster physics, there are few directmeasurements of the ICM velocity structure. Hitomi measured line broadening inPerseus through its groundbreaking high resolution spectrum, but due to its losswe may have to wait until Athena.s 2028 launch to obtain similar data. Here wepropose a novel technique to use the fluorescent background emission lines seenin the EPICPN detector to calibrate the energy scale to a high precision and someasure bulk motions within the Virgo and Centaurus clusters. We shall reachaccuracies of 100200 km/s around the inner 7 arcmin, increasing to 400 km/s at16 arcmin radius. Secondary aims include using the RGS grating spectra toconstrain/measure the velocity of cool material around the central AGN. truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]