  In this contribution we present the first numerical simulations of a
relativistic outflow propagating through the inner hundreds of parsecs of its
host galaxy, including atomic and ionised hydrogen, and the cooling effects of
ionisation. Our results are preliminary, but we observe efficient shock
ionization of atomic hydrogen in interstellar clouds. The mean density of the
interstellar medium in these initial simulations is lower than that expected in
typical galaxies, which makes cooling times longer and thus no recombination is
observed inside the shocked region. The velocities achieved by the shocked gas
in the simulations are in agreement with observational results, although with a
wide spectrum of values.
