Basics of gas-dynamics and radiative transfer - Introduction to out-of-equilibrium high energy flows

This article is intended to review some basics of gas-dynamics(1) (Sect. 1) and radiative transfer (Sect. 2) which are the necessary background to int roduce out-of-equilibrium high energy flows. The two first sections deal wi th general aspects, the more specific problem of out-of-equilibrium flows i s tackled in Sect. 3 through the example of radiative shock waves.