  The crisis of the standard cooling flow model brought about by Chandra and
XMM-Newton observations of galaxy clusters, has led to the development of
several models which explore different heating processes in order to assess if
they can quench the cooling flow. Among the most appealing mechanisms are
thermal conduction and heating through buoyant gas deposited in the ICM by
AGNs. We combine Virgo/M87 observations of three satellites (Chandra,
XMM-Newton and Beppo-SAX) to inspect the dynamics of the ICM in the center of
the cluster. Using the spectral deprojection technique, we derive the physical
quantities describing the ICM and determine the extra-heating needed to balance
the cooling flow assuming that thermal conduction operates at a fixed fraction
of the Spitzer value. We assume that the extra-heating is due to buoyant gas
and we fit the data using the model developed by Ruszkowski and Begelman
(2002). We derive a scale radius for the model of $\sim 5$ kpc, which is
comparable with the M87 AGN jet extension, and a required luminosity of the AGN
of a $few \times 10^{42}$ erg s$^{-1}$, which is comparable to the observed AGN
luminosity. We discuss a scenario where the buoyant bubbles are filled of
relativistic particles and magnetic field responsible for the radio emission in
M87. The AGN is supposed to be intermittent and to inject populations of
buoyant bubbles through a succession of outbursts. We also study the X-ray cool
component detected in the radio lobes and suggest that it is structured in
blobs which are tied to the radio buoyant bubbles.

Astrophysics