Relativistic thermal plasmas - time development of electron-positron pair concentration

The time evolution of a relativistic pair-equilibrium plasma confined in a uniformly or impulsively heated sphere is investigated analytically, starting from initial conditions appropriate for a plasma in an AGN. The formulations for pair processes, radiative transfer, photon production, Compton scattering, and the energy equations are explained, and numerical results are presented in extensive graphs and characterized in detail. It is found that the pair equilibrium is stable under constant heating, but that extreme changes in electron temperature, pair density, and luminosity occur for larger amounts of impulsive heating. 25 references