Locally Optimally-Emitting Clouds and the Variable Broad Emission Line Spectrum of NGC 5548

Abstract

[abridged] We test the ``locally optimally-emitting clouds'' (LOC) model against the extensive spectroscopic data base of the Seyfert~1, NGC 5548. The time-averaged, integrated-light UV broad emission line spectrum from the 1993 {\em HST} monitoring campaign is reproduced via the optimization of three global geometric parameters: the outer radius, the index controlling the radial cloud covering fraction of the continuum source, and the integrated cloud covering fraction. We make an {\em ad~hoc} selection from the range of successful models, and for a simple spherical BLR geometry we simulate the emission line light curves for the 1989 {\em IUE} and 1993 {\em HST} campaigns, using the respective observed UV continuum light curves as drivers. We find good agreement between the predicted and observed light curves and lags --- a demonstration of the LOC picture's viability as a means to understanding the BLR environment. Finally, we discuss the next step in developing the LOC picture which involves the marriage of echo-mapping techniques with spectral simulation grids such as those presented here, using the constraints provided by a high quality, temporally well-sampled spectroscopic data set.

24 pages (AASTeX, v5.02), 8 separate figures, in press with the Astrophysical Journal

References in corpus (4)

• Central Masses and Broad-Line Region Sizes of Active Galactic Nuclei: I. Comparing the Photoionization and Reverberation Techniques
• Keplerian Motion of Broad-Line Region Gas as Evidence for Supermassive Black Holes in Active Galactic Nuclei
• On the Reliability of Cross Correlation Function Lag Determinations in Active Galactic Nuclei
• Modeling Variable Emission Lines in AGNs: Method and Application to NGC 5548

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