Plasma properties of the broad line emitting region in active galactic nuclei

Abstract

In order to probe the physical properties of the emitting plasma in the broad line region (BLR) of active galactic nuclei (AGN), we perform a number of numerical simulations with the photoionization code CLOUDY. We investigate the Bakner and helium line ratios in order to find conditions in the BLR where so-called Boltzmann-plot (BP) method is applicable. We foimd correlations between average temperature, hydrogen density and He II/He I line ratio in the case where BP is present. © 2009 American Institute of Physics.