X-Ray Line Tomography of AGN-induced Motion in Clusters of Galaxies

The thermal broadening of emission lines of heavy ions is small enough such that Doppler shifts due to bulk motions may be detected with the next generation of X-ray observatories. This opens up the possibility of studying gas velocities in the intracluster medium. Here we study the effect of bulk motions induced by a central active galactic nucleus (AGN) on the emission lines around the Fe XXV complex. We have modeled the evolution of AGN-induced bubbles in a realistic cosmological framework and studied the resulting Fe XXV line profiles. We found that in clusters with AGN feedback, motions induced by the inflation of bubbles and their buoyant rise lead to distinct features in the iron emission lines that are detectable with a spectral resolution of ~10 eV. These observations will help us to determine the mechanical energy that resides in the bubbles and thereby the kinetic luminosity of the AGN.