  We have performed the first three-dimensional relativistic hydrodynamic
simulations of extragalactic jets of pure leptonic and baryonic plasma
compositions propagating into a hydrostatic intracluster medium environment.
The numerical simulations use a general equation of state for a multi-component
relativistic gas which closely reproduces the Synge equation of state for a
relativistic perfect gas. We find that morphological and dynamical differences
between leptonic and baryonic jets are much less evident than those between hot
and cold jets. In all these models, the jets first propagate with essentially
constant velocities within the core radius of the intracluster medium and then
accelerate progressively so as to increase the jet advance velocity by a factor
of between 1.2 and 1.6 at the end of simulations, depending upon the models.
The temporal evolution of the average cavity pressure is not consistent with
that expected by the extended theoretical model even if the average cavity
pressure decreases as a function of time with a power-law. Our simulations
produce synthetic radio images that are dominated by bright hot spots and
appear similar to observations of the extended radio galaxies with collimated
radio jets. These bright radio lobes would be visible as dark regions in X-ray
images and are morphologically similar to observed X-ray cavities in the
intracluster medium. This supports the expectation that the bow shock
surrounding the head of the jet is important mechanism for producing X-ray
cavities in the intracluster medium. Although there are quantitative
differences among the models the total radio and X-ray intensity curves show
qualitatively similar trends in all of them.
