X-ray spectra of active galactic nuclei

Active galactic nuclei were studied using the Einstein Monitor Proportional Counter (MPC). The MPC data analysis methods are described, including calibration, background subtraction, and spectral analysis. The low energy imaging instruments on Einstein are used in conjunction with the MPC to measure smaller column densities or soft excesses in several objects. The MPC data also reveal the ubiquity of variability on timescales of days to months, with lower luminosity Seyferts displaying the largest excursions. The X ray spectral results are discussed in terms of the synchrotron self-Compton mechanism and the nonthermal radio spectra which have similar power law indices of approximately 0.7. A generalized photoionization code was developed with particular attention to X-ray effects and recent atomic data. It is shown that X-ray photoionization can account for the optical emission lines in low ionization AGN which were previously thought to be shock heated.