Numerical Simulations of Interaction between Stellar Wind and Interstellar Medium

Abstract

Hydrodynamic interaction between supersonic spherical wind emitted from an astronomical object and a uniform streaming flow is simulated numerically assuming the flow to be axisymmetric, adiabatic and inviscid. Examples of such a phenomenon are a comet in the solar wind, and the solar wind or a stellar wind in an interstellar medium. Three cases of the incident flow, i.e., subsonic, supersonic and hypersonic flow, are considered. Discontinuities in the flow, i.e., a bow shock, a contact surface, an inner shock, a Mach disc and a slip surface are identified. The contact surface and the slip surface are found to be Kelvin-Helmoholtz unstable. Other instabilities occurring near the stagnation region and the inner shock are also found.