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Session 51 - Active Galactic Nuclei & Quasars.
Oral session, Thursday, June 12
North Main Hall A,

[51.01] Line emission and absorption characteristics due to stellar winds in active galactic nuclei

J. Taylor (NASA/GSFC, U. Maryland), D. Kazanas (NASA/GSFC)

I will present synthetic spectra and response functions of the red giant stellar line emission model of active galactic nuclei (e.g., Kazanas 1989). Our results agree with the fundamental line emission characteristics of AGNs within the model uncertainties provided the following new assumptions are made: 1) the mean stellar mass loss rates decrease with distance from the black hole, and 2) the mean ionization parameters are lower than what was postulated in Kazanas (1989). In addition, I will also discuss several interesting features of stellar wind models. For instance, provided the density of the intercloud (interstellar) medium is high enough, the stellar winds are shaped similar to comets, with the shock fronts having higher densities than the tails. As a result, the densities in the inverse Stromgren regions of the outbound clouds are lower than those of the inbound clouds. For models with a BLR occulting accretion disk, this results in line emission and absorption (BAL) shifts despite having a cloud phase space distribution function that is independent of the velocity vector direction. More specifically, for our models (in which the mean ionization parameter falls with distance from the black hole), the broadest line emission/absorption is red-shifted and the narrowest emission and absorption is blue-shifted for lines similar to C IV, N V, and O VI. On the other hand, Lya has a weaker dependence upon the ionization parameter and correspondingly has smaller shifts. These results are fully consistent with the observation that the C IV red wing responds faster than the blue wing in NGC 5548 (e.g., Done amp; Krolik 1996).

Program listing for Thursday