Long-term FRII jet evolution in dense environments
  We present long-term numerical three-dimensional simulations of a
relativistic outflow propagating through a galactic ambient medium and
environment, up to distances $\sim 100$~kpc. Our aim is to study the role of
dense media in the global dynamics of the radio source. We use a relativistic
gas equation of state, and a basic description of thermal cooling terms. In
previous work, we showed that a linear perturbation could enhance the jet
propagation during the early phases of evolution, by introducing obliquity to
the jet reverse shock. Here, we show that this effect is reduced in denser
media. We find that the dentist-drill effect acts earlier, due to slower jet
propagation and an increased growth of the helical instability. The global
morphology of the jet is less elongated, with more prominent lobes. The
fundamental physical parameters of the jet generated structure derived from our
simulations fall within the estimated values derived for FRII jets in the 3C
sample. In agreement with previous axisymmetric and three dimensional
simulations in lower density media, we conclude that shock heating of the
interstellar and intergalactic media is very efficient in the case of powerful,
relativistic jets.
