  We have calculated FeII emission line strengths for Active Galactic Nuclei
Broad-Line Regions using precise radiative transfer and Iron Project atomic
data. We improve the treatment of all previously considered excitation
mechanisms for the FeII emission, continuum fluorescence, collisional
excitation, fluorescence by self-overlap among the iron lines, and fluorescent
excitation by Lyman-alpha. We demonstrate that Lyman-alpha fluorescence is of
fundamental importance in determining the strength of the FeII emission. In
addition to enhancing the ultraviolet and optical FeII flux, Lyman-alpha
fluorescence also results in significant near-infrared FeII emission in the
8500-9500 Angstrom wavelength range. New observations are suggested to probe
this effect in strong FeII emitting quasars.

Astrophysics