A simple and efficient high-resolution shock-capturing method for relativistic fluid dynamics

Relativistic flows play an essential role in high energy astrophysics, and relativistic shocks are supposed to be the place where particle acceleration occurs. Among the astrophysical sources of such flows and shocks there are AGNs, and the related jets, the GRB fireball, and pulsar wind nebulae. We present an easy to implement multidimensional shock-capturing relativistic hydrodynamics (RHD) scheme. RHD numerical schemes are generally more expensive than their corresponding Eulerian version, essentially for the complexity of the relation between conservative and primitive variables. Our scheme is based on third order CENO reconstruction and on averaged Riemann solvers which do not require characteristic decomposition. The scheme is efficient and robust, even in multidimensional simulations, and can cope with very high Lorentz factors, giving results comparable with those of more sophisticated methods.