  Feedback from central supermassive blackholes is often invoked to explain the
low star formation rates in massive galaxies at the centers of galaxy clusters.
However, the detailed physics of the coupling of the injected feedback energy
with the intracluster medium is still unclear. Using high-resolution
magnetohydrodynamic cosmological simulations of galaxy cluster formation, we
investigate the role of anisotropic thermal conduction in shaping the
thermodynamic structure of clusters, and, in particular, in modifying the
impact of black hole feedback. Stratified anisotropically conducting plasmas
are formally always unstable, and thus more prone to mixing, an expectation
borne out by our results. The increased mixing efficiently isotropizes the
injected feedback energy which in turn significantly improves the coupling
between the feedback energy and the intracluster medium. This facilitates an
earlier disruption of the cool core, reduces the star formation rate by more
than an order of magnitude, and results in earlier quenching despite an overall
lower amount of feedback energy injected into the cluster core. With
conduction, the metallicity gradients and dispersions are lowered, aligning
them better with observational constraints. These results highlight the
important role of thermal conduction in establishing and maintaining quiescence
of massive galaxies.
