I've reviewed the continuum, emission-line, and absorption-line properties of primarily low-redshift AGN, concentrating on the first observations available from FUSE. Composite far-UV spectra of QSOs developed from a sample now consisting of over 200 AGN (Telfer et al. 2000) confirms the result of Zheng et al. (1997) that the continuum spectral index breaks at ~ 1000 Å to a steep power law of spectral index ~ 1.8. Observations of individual objects such as 3C 273 (Kriss et al. 1999) show a qualitatively similar feature. Initial results from FUSE (with contemporaneous HST and ground-based observations) also show that the spectral energy distributions of low-redshift AGN are peaking in the 1000-1200 Å range. This implies that there is little evolution in the mean shape of the ionizing continuum from z > 1 to the current epoch.
Nearly all Type 1 AGN observed with FUSE show strong, broad O VI emission. The broad O VI emission of AGN as revealed by HUT and FUSE is significantly stronger in low-redshift objects. The FUSE observations also show that strong, narrow O VI emission is prominent in several Type 1 AGN. In most cases this appears to be emission from the narrow-line region made relatively more prominent because the continuum and broad lines are in a relatively low state. However, NGC 3516 presents an interesting (and not yet understood) exception since the narrow O VI doublet has an optically thick 1:1 intensity ratio.
FUSE observations of O VI and high-order Lyman-line absorption in AGN with warm absorbers offers a powerful new tool for the study of the warm absorbing gas. The FUSE resolution reveals multiple kinematic components, and the O VI absorption lines often identify the highest ionization system likely to be directly associated with the warm absorber. Proposed monitoring observations may help to pinpoint the location and physical conditions in this important structural component of the nuclear region in AGN.
Acknowledgments. The FUSE results are due in large part to the help of the FUSE Team and the FUSE AGN Working Group, particularly M. Brotherton and W. Zheng. R. Telfer, J. Kim, and A. Koratkar also made significant contributions. This work was supported in part by NASA contract NAS5-32985 for the FUSE project, NASA Long Term Space Astrophysics grant NAGW-4443, and grant GO-08144.01-97A from the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555.