AGN feedback and non-thermal pressure in cooling flows.

E.Churazov, W.Forman, A.Vikhlinin, S.Tremaine, O.Gerhard, C.Jones, MPA, IKI, CFA, IAS, MPE

The comparison of gravitational potential profiles of elliptical galaxies derived from X-ray and optical data suggests that the combined contribution of cosmic rays, magnetic fields and micro-turbulence makes ~10% of the gas thermal pressure. This result is consistent with the current paradigm of cool cluster cores, based on the assumption that AGN activity regulates the thermal state of the gas, but places tight constraints on the AGN feedback mechanism.