Generation of a Fireball in AGN Hot Plasmas
  Motivated by relativistic jets observed in active galactic nuclei (AGN), we simulate outflows of electron-positron pairs strongly coupled with photons from normal electron-proton plasmas. Using multi-fluid approximation and a Monte Carlo method of radiative transfer, we obtain spherically symmetric, steady solutions of radiation and pair outflows for the luminosity $L \leq 10^{47}$ erg ${\rm s^{-1}}$. For microphysics, Coulomb scattering, Compton scattering, bremsstrahlung, electron-positron pair annihilation and creation are taken into account. Although a significant amount of pairs outflow by powerful radiative force with a mildly relativistic velocity, the temperature is not high enough to avoid pair annihilation before the fireball becomes optically thin to scattering. Several caveats in the simulations are also discussed. 
Katsuaki Asano and Fumio Takahara