A Structure for Quasars

This paper proposes a simple, empirically derived, unifying structure for the inner regions of quasars. This structure is constructed to explain the broad absorption line (BAL) regions, the narrow ‘associated’ ultraviolet and X-ray ‘ionized’ absorbers (NALs); and is also found to explain the broad emission line regions (BELR), and several scattering features, including a substantial fraction of the broad X-ray Iron-K emission line, and the bi-conical extended narrow emission line region (ENLR) structures seen on large kiloparsec scales in Seyfert images. The model proposes that a funnel-shaped thin shell outflow creates all of these features. The wind arises vertically from a narrow range of radii on a disk at BELR velocities. Radiation force then accelerates the flow radially, so that it bends outward to a cone angle of ∼60, and has an divergence angle of ∼6, to give a covering factor of ∼10%. When the central continuum is viewed from the side, through this wind, narrow high ionization ‘associated’ ultraviolet absorption lines and the X-ray ‘ionized absorbers’ are seen, as in many low luminosity active galactic nuclei. When viewed end-on the full range of velocities is seen in absorption with a large total column density, giving rise to the broad absorption lines systems seen in a minority of quasars, the BALQSOs. The wind is both warm (∼ 10 K) and highly ionized. This warm highly ionized medium (WHIM) has a density of ∼ 10 cm, putting it in pressure equilibrium with the BELR clouds; the BELR is then a cool phase embedded in the overall outflow, avoiding cloud destruction through shear. The wind has the correct ionization parameter and filling factor for this. The high and low ionization zones of the BELR correspond to the cylindrical and conical regions of the wind, since the former is exposed to the full continuum, while the latter receives only the continuum filtered by the former. The warm wind is significantly Thomson thick along the radial flow direction, producing the polarized optical continuum found in BALs, but is only partially ionized, creating a broad fluorescent 6.4 keV Fe-K emission line, and >10 keV