AGN Feedback in the Hot Halo of NGC 4649
  Using the deepest available $\textit{Chandra}$ observations of NGC 4649 we
find strong evidences of cavities, ripples and ring like structures in the hot
interstellar medium (ISM) that appear to be morphologically related with the
central radio emission. These structures show no significant temperature
variations in correspondence with higher pressure regions
($0.5\mbox{kpc}<r<3\mbox{kpc}$). On the same spatial scale, a discrepancy
between the mass profiles obtained from stellar dynamic and $\textit{Chandra}$
data represents the telltale evidence of a significant non-thermal pressure
component in this hot gas, which is related to the radio jet and lobes. On
larger scale we find agreement between the mass profile obtained form
$\textit{Chandra}$ data and planetary nebulae and globular cluster dynamics.
The nucleus of NGC 4649 appears to be extremely radiatively inefficient, with
highly sub-Bondi accretion flow. Consistently with this finding, the jet power
evaluated from the observed X-ray cavities implies that a small fraction of the
accretion power calculated for the Bondi mass accretion rate emerges as kinetic
energy. Comparing the jet power to radio and nuclear X-ray luminosity the
observed cavities show similar behavior to those of other giant elliptical
galaxies.
