We present a survey of 72 Seyfert galaxies and quasars observed by the Far Ultraviolet Spectroscopic Explorer. We have determined that 72 of 253 available active galactic nuclei (AGNs) targets are viable targets for detection of intrinsic absorption lines. We examined these spectra for signs of intrinsic absorption in the O VI doublet (λλ1031.9, 1037.6) and Lyβ (λ1025.7). The fraction of Seyfert 1 galaxies and low-redshift quasars at z ≲0.15 that show evidence of intrinsic UVabsorption is ∼50%, which is slightly lower than that found by Crenshaw et al. (1999), who found 60% based on a smaller sample of Seyfert 1 galaxies observed with the Hubble Space Telescope. With this new fraction we find a global covering factor of the absorbing gas with respect to the central nucleus of ∼0.4. Our survey is to date the largest search for intrinsic UV absorption with high spectral resolution and is the first step toward a more comprehensive study of intrinsic absorption in low-redshift AGNs.
All Science Journal Classification (ASJC) codes
- Astronomy and Astrophysics
- Space and Planetary Science