Accretion Disk Winds from Active Galactic Nuclei: A Model for the Dynamics of Broad Absorption Line Regions

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Session 34 -- Spectroscopy of AGN II: Broad Lines and Spectral Evolution
Oral presentation, Monday, 9, 1995, 2:00pm - 3:30pm

[34.01] Accretion Disk Winds from Active Galactic Nuclei: A Model for the Dynamics of Broad Absorption Line Regions

J. Chiang, N. Murray, S. A. Grossman (CITA), G. M. Voit (Johns Hopkins Univ.)

We present a dynamical model in which the broad absorption lines (BALs) seen in some quasar spectra form in a smooth non-spherical wind from an accretion disk. On the inner edge of this wind, entrained dense gas blocks soft x-rays but transmits ultra-violet photons, allowing radiation pressure on resonance lines to accelerate the outflow to $\sim 0.1 c$. The wind produces emission lines at most viewing angles, contributing significantly to the formation of the broad emission lines that characterize active galactic nuclei. We also note that the dynamical requirements of this model are consistent with recent HST results that BAL regions are smaller than previously thought and recent ROSAT results that confirm that there is an absence of soft X-rays in QSOs known to exhibit BALs.

Monday program listing