Principal Investigator

R S Sutherland Astronomy, RSAA, ANU

Project Title

The Impact of Realistic Plasma Cooling Processes on the Hydrodynamics of Astrophysical Shockwaves

Brief Description for General Publications

We are undertaking very high resolution hydrodynamical simulations of hypersonic radiative wall shocks in 3 dimensions, using computed non-equilibrium cooling. A Mach 15-20 shockwave is propagated into media with density fluctuations with both power--law and gaussian spectra, and the development of the post shock thermal instabilities and turbulence is examined. We have shown in 2D that, due to the intrinsic scales introduced by the cooling process, extremely high resolutions are required to achieve asymptotic solutions. The post shock turbulence is no longer a simple power--law, with strong dissipation occurring at intermediate scales. A fractal dimensional treatment of the resulting structures gives useful means of estimating the cooling efficiencies of these strong shocks compared to uniform or even steady models. We are now in the position to use the massive parallel SC computer to compute fully 3D models to correctly model the turbulence in the cooling zone. This is will lead to unique new insights into the physics of hypersonic astrophysical shocks - especially in the context of galaxy formation.