Simultaneous Ultraviolet and X‐Ray Observations of the Seyfert Galaxy NGC 4151. II. Physical Conditions in the UV Absorbers

We present a detailed analysis of the intrinsic absorption in the Seyfert 1galaxy NGC 4151 using UV spectra from the HST/STIS and FUSE, obtained 2002 Mayas part of a set of contemporaneous observations that included Chandra/HETGSspectra. In our analysis of the Chandra spectra, we determined that the softX-ray absorber was the source of the saturated UV lines of O VI, C IV, and N Vassociated with the absorption feature at a radial velocity of ~ -500 km/sec,which we referred to as component D+E. In the present work, we have derivedtighter constrains on the the line-of-sight covering factors, densities, andradial distances of the absorbers. We find that the Equivalent Widths (EWs) ofthe low-ionization lines associated with D+E varied over the period from 1999July to 2002 May. The drop in the EWs of these lines between 2001 April and2002 May are suggestive of bulk motion of gas out of our line-of-sight. Ifthese lines from these two epochs arose in the same sub-component, thetransverse velocity of the gas is ~ 2100 km/sec. Transverse velocities of thisorder are consistent with an origin in a rotating disk, at the roughly radialdistance we derived for D+E.Comment: 51 pages, including 12 figures. Accepted for publication in ApJ Supplement