  Using observations from the Chandra X-ray Observatory and Giant Metrewave
Radio Telescope, we examine the interaction between the intracluster medium and
central radio source in the poor cluster AWM 4. In the Chandra observation a
small cool core or galactic corona is resolved coincident with the radio core.
This corona is capable of fuelling the active nucleus, but must be
inefficiently heated by jet interactions or conduction, possibly precluding a
feedback relationship between the radio source and cluster. A lack of clearly
detected X-ray cavities suggests that the radio lobes are only partially filled
by relativistic plasma. We estimate a filling factor of phi=0.21 (3 sigma upper
limit phi<0.42) for the better constrained east lobe. We consider the particle
population in the jets and lobes, and find that the standard equipartition
assumptions predict pressures and ages which agree poorly with X-ray estimates.
Including an electron population extending to low Lorentz factors either
reduces (gamma_min=100) or removes (gamma_min=10) the pressure imbalance
between the lobes and their environment. Pressure balance can also be achieved
by entrainment of thermal gas, probably in the first few kiloparsecs of the
radio jets. We estimate the mechanical power output of the radio galaxy, and
find it to be marginally capable of balancing radiative cooling.
