ON THE ORIGIN OF BROAD FE K-ALPHA AND H-I H-ALPHA LINES IN ACTIVE GALACTIC NUCLEI

We examine the properties of the Fe emission lines that arise near 6.4 keV in the ASCA spectra of AGNs. Our emphasis is on the Seyfert 1 gal axies where broad and apparently complex Fe K alpha emission is observ ed. We consider various origins for the line but focus on the pros and cons for line-emitting accretion disk models. We develop a simple mod el of an illuminated disk capable of producing both X-ray and optical lines. The model is able to reproduce the observed Fe K alpha FWHM rat io as well as the radii of maximum emissivity implied by the profile r edshifts. The overall profile shapes, however, do not fit well the pre dictions of our disk illumination model nor do we derive always consis tent disk inclinations for the two lines. We conclude that the evidenc e for and against an accretion disk origin for the Fe K alpha emission is equivocal. The bulk of the data requires a very disparate set of l ine fits, shedding little light on a coherent physical model. We brief ly consider alternatives to disk-emission and show that a simple bicon e model can reproduce the Fe line profiles equally well.