Mass-loaded astronomical flows – I. General principles and their application to RCW 58

We discuss the general principles of mass addition to astrophysical flows via hydrodynamic mixing. We argue that in the absence of strong radiative cooling, a sustained one-dimensional mass-loaded flow will statistically mimic a steady flow of constant adiabatic Mach number about equal to unity. This proposition receives powerful support from observational data for the Wolf–Rayet wind-blown nebula RCW 58.