A hot patch of gas surrounded by a cooler background is allowed to diffuse in the presence of a circular magnetic field.
Point explosion with conduction
Sedov-Taylor blast wave problem. This problem is a good test to determine the accuracy of coupling between two distinct physical processes: hydrodynamics and diffusion. We simulate three different configurations of the blast wave problem, the classical adiabatic blast wave test (left panel), the blast wave test with isotropic conduction (middle panel), and the blast wave test with anisotropic conduction (right panel) in 3D. The magnetic field in the anisotropic blast wave test points in the x-direction. The size of the box is (100 pc)^3.
Heat-Flux-Driven Buoyancy Instability (HBI)
The dynamics of a rapidly conducting stratified plasma differs from that of an adiabatic fluid. The temperature gradient and the local orientation of the magnetic field determine the plasma’s convective stability. When the temperature increases with height, the convective instability is known as the heat-flux-driven buoyancy instability (HBI). This instability saturates by reorienting the magnetic fields perpendicular to gravity. In the following visualization gravity points downwards. The size of the box is (0.1 cm)^2.
Magneto Thermal Instability (MTI)
When the temperature decreases with height, the convective instability is known as the magneto thermal instability (MTI). This instability does not saturate and can drive sustained convection. In the following visualization gravity points downwards. The size of the box is (0.1 cm)^2. The HBI and MTI make the ICM unstable even if dS/dr > 0, which has important implications for the coupling between the injected feedback energy from the central blackhole and the ICM.
