  We present Chandra X-ray and VLA radio observations of the radio galaxy
3C305. The X-ray observations reveal the details of the previously known
extended X-ray halo around the radio galaxy. We show using X-ray spectroscopy
that the X-ray emission is consistent with being shock-heated material and can
be modelled with standard collisional-ionization models, rather than being
photoionized by the active nucleus. On this basis, we can make a
self-consistent model in which the X-ray-emitting plasma is responsible for the
depolarization of some regions of the radio emission from the jets and
hotspots, and to place lower and upper limits on the magnetic field strength in
the depolarizing medium. On the assumption that the X-ray-emitting material,
together with the previously-known extended emission-line region and the
outflow in neutral hydrogen, are all being driven out of the centre of the
galaxy by an interaction with the jets, we derive a detailed energy budget for
the radio galaxy, showing that the X-ray-emitting gas dominates the other
phases in terms of its energy content. The power supplied by the jets must be ~
10^43 erg/s.
