Thermodynamics of a homogeneous mixture of gas, radiation, and turbulence

Subject to certain constraints, the equilibrium thermodynamics of a mixture of ionizing gas, blackbody radiation, and homogeneous turbulence is worked out in some detail. Specific heats and adiabatic exponents (Chandrasekhar's gammas) are calculated. The adiabatic exponents show only a weak dependence on the turbulent pressure and the turbulent energy. This dependence is weakest under conditions of strong partial ionization of the gas, or when the relative pressure due to radiation is very high. Analytic expressions and numerical examples are both given, and possible astrophysical applications are briefly discussed.