Reprocessing of soft X-ray emission lines in black hole accretion disks

By means of a Monte Carlo code that accounts for Compton scattering and photoabsorption followed by recombination, we investigate the radiation transfer of Lyalpha, Healpha, and recombination continua photons of H- and He-like C, N, O, and Ne produced in the photoionized atmosphere of a relativistic black hole accretion disk. We find that photoelectric opacity causes significant attenuation of photons with energies above the O VIII K edge, that the conversion efficiencies of these photons into lower energy lines and recombination continua are high, and that accounting for this reprocessing significantly (by factors of 21%-105%) increases the flux of the Lyalpha and Healpha emission lines of H- and He-like C and O escaping the disk atmosphere.