Hydrodynamical simulations of relativistic jets

We have performed simulations of relativistic pressure-matched slab jets with beam Lorentz factors in the range 4. 1 to 22.4 using a modern high-resolution shock-capturing technique based on an approximate relativistic Riemann solver. Our results show that the basic structural components found in Newtonian simulations, i.e. beam, cocoon, working surface and bow shock, are also present in relativistic jets. We further find that the head of the jet propagates at relativistic speed which depends on the beam velocity in a very non-linear way, and that relativistic jets seem to be more stable than Newtonian ones. Finally, our preliminary results strongly support the necessity of a more detailed study of the morphology and dynamics of relativistic jets