Back to Volume
Paper: Testing Disk-Wind Models with Quasar CIV 1549Å Associated Absorption Lines
Volume: 460, AGN Winds in Charleston
Page: 226
Authors: Vestergaard, M.
Abstract: Narrow associated C IV 1549Å absorption lines (NALs) with a rest equivalent width EW ≥3 Å detected in z ∼ 2 radio-loud and radio-quiet quasars, (a) exhibit evidence of an origin in radiatively accelerated gas, and (b) may be closely related to broad absorption line (BAL) outflows. These NALs and the few BALs detected in this quasar sample obey key predictions of models of radiatively driven disk-winds in which (1) the local disk luminosity launches the wind, (2) the central UV radiation drives it outwards, and (3) the wind acceleration (i.e., terminal velocity) depends on the strength of the X-ray to UV emission ratio, i.e., αOX. The latter means that quasars with flat αOX (like radio-louds) should not have strong, high-velocity (BAL-like) outflows. These results are of interest not only to studies of disk wind scenarios and quasar structure, but also to studies of quasar feedback: NALs that originate in powerful outflows are potential probes of quasar feedback on its environment, since NALs are more commonly occuring than BALs, irrespective of quasar radio properties (Vestergaard 2003).
Back to Volume