Radiation pressure-driven shocks in winds from hot stars

The authors outline the dynamical theory of radiation pressure-driven shocks in winds from early-type stars. After isolating the principal parameters needed for a description of these shocks, namely their speeds relative to incoming material and their column densities, the authors estimate the shocks' principal properties as functions of these parameters. For the special case of time-steady shocks detailed numerical calculations are presented of the shocks' internal structure: density, ionization state, temperature, and flow velocity as functions of position; and X-ray emissivity, UV line emissivity, and total radiation force as functions of shock velocity and postshock column density.