ABSTRACT

We have studied the effects on line emission due to the reprocessing of AGN continuum by cool (T ≲ 104 K) stellar winds from stars, such as those from red giants, expected to be present in the region (Fabian 1979; Penston, 1988; Norman and Scoville 1988; Kazanas 1989). Using model stellar phase space distribution functions appropriate for stellar clusters with black holes, we have calculated the expected covering factors, line profiles, and two dimensional line transfer functions of these systems. Our stellar models contain between 107 and 108 stars within a parsec from the central source, of which we assume a fraction are able to reprocess continuum radiation. The line profiles of our models have FWHM up to 5,000 km sec-1 for black hole masses between 107 and 108 solar masses and covering factors up to approximately 10-1. The line transfer functions we obtain peak at lags from 5 to 200 days for optically thick clouds. Forbidden line emission has also been studied for this effect. For some of our models, the wind line emission has been found to be quite significant.

INTRODUCTION

Active galactic nuclei (AGN) have very high stellar densities. That the effects of stars in the study of AGN has been largely ignored is somewhat surprising. In addition to the stellar densities, the X-ray continuum radiation is also quite high in AGN. We have calculated the magnitude and observational characteristics of line emission from reprocessing of the central continuum radiation of stellar winds of stars in AGN.