Heat Pumps in Clusters: AGN-Mitigated Feedback by Thermal Conduction

Radio mode feedback in galaxy clusters, groups, and early type galaxies stipulates that jet-inflated cavities heat the ISM and IGM of their hosts halo. Energetically, this association is plausible, but the detailed transfer of energy in these systems is still poorly understood. We show that entropy transport by jets-inflated bubbles leads to enhanced thermal conduction, which can heat the lowest entropy gas of the atmosphere much more efficiently than conduction would in the absence of jets, even in light of the fact that conduction in these systems may be suppressed substantially below the Spitzer value. In effect, jets act like geo-thermal heat pumps that allow low-entropy gas to be placed in thermal contact with a large heat bath, with net efficiencies exceeding 100%. I will present results from our ongoing analytic and computational study of this mechanisms, focusing on the Perseus Cluster, the gold standard in cluster studies.