Convection Movie: Conducting vs Adiabatic Plasma
(see paper for details)
Shown are the 2-D (phi=constant) slices of runs with anisotropically conducting plasma (top)
and adiabatic plasma (bottom). Cosmic rays are put in with a subsonic source term confined to 30 degrees about the polar axis. The two simulations are identical, except for thermal conduction along field lines in one of the cases and adiabatic (no heat conduction) plasma in the other.
It is much easier to mix the conducting plasma as compared to the stably stratified adiabatic plasma. With a weak stable
buoyant response (as compared to an adiabatic plasma) thermally conducting plasma is stirred vigorously; this is analogous to the fact that turbulence arises in stably
stratified fluids if the Richardson number (the ratio of stable
buoyant force to the turbulent shear force) is small enough (<1/4). For the same reason, mixing with isotropically conducting plasma (not shown here) is even more vigorous than either anisotropically conducting or adiabatic plasmas.
See the paper for details on the effect of turbulent forcing in adiabatic, anisotropically conducting, and
isotropically conducting plasmas.
Log10(metallicity), Log10(pcr/d^1.3333), Log10(pcr/p)