On the Energetics and Momentum Distribution of Bow Shocks and Colliding Winds

Abstract

We discuss recent progress in analytic modeling of stellar wind bow shocks and colliding winds. For thin, radiative shocked layers in steady-state, the shape of the layer as well as its internal flux of mass and momentum are found from the conservation laws of mass, momentum and angular momentum. For the case that the shocked gas is well-mixed, the velocity distribution and mass column density of shocked material are also obtained. These solutions are extended to the problem of a jet bow shock, treated as a non-isotropic “wind” interacting with the ambient medium. We also examine the shell energetics for these simple analytic models. The constraint of conservation of momentum leads to an upper limit to the efficiency of thermalization and radiation of the pre-shock wind kinetic energy. Calculations are presented of this thermalization rate as a function of the input momentum rates of the pre-shock winds.