Intermediate Gas Phases within Turbulent Radiative Mixing Layers

Abstract

Turbulent radiative mixing layers (TRMLs) occur ubiquitously in astrophysical environments; e.g., TRMLs are prevalent within galactic outflows at the intersections between hot supernovae ejecta and cold molecular clouds. A velocity shear between the rapidly outflowing hot gas and cold clouds drives the Kelvin–Helmholtz instability producing TRMLs, with radiative cooling dominating the heat transfer between the gas phases. Using hydrodynamic simulations, we have modeled TRMLs for a range of overdensities (100, 1000, 3000) applied to cold phase temperatures of 400, 103, and 104 K. The production of an intermediate gas phase at the interface between the hot and cold phases is consistently observed at ∼104 K for molecular clouds, in agreement with larger-scale wind-tunnel simulations.