Discovery of Associated Absorption Lines in an X-Ray Warm Absorber:[ITAL]Hubble Space Telescope[/ITAL] Observations of PG 1114+445

Abstract

The unified picture of X-ray/UV absorbers offers a unique opportunity to probe the nuclear environment of active galactic nuclei. To test the unified absorber scenario and to understand the physical properties of the absorber, we obtained the first UV spectrum of PG 1114+445 using the Hubble Space Telescope (HST) Faint Object Spectrograph. PG 1114+445 is known to have an X-ray ionized ("warm") absorber, so that UV absorption is predicted. The HST spectrum clearly shows strong UV absorption lines due to Lyα, C IV, and N V, blueshifted by ~530 km s-1 with respect to the quasar redshift. Since both X-ray and UV absorbers are rare in radio-quiet quasars, these observations argue strongly that the X-ray and UV absorbers are closely physically related, perhaps identical. We place constraints on the parameters of the absorber and conclude that the mass outflow rate is comparable to the accretion rate in PG 1114+445.