SPATIALLY RESOLVED FAR-ULTRAVIOLET SPECTROSCOPY OF THE NUCLEAR REGION OF NGC 1068

We carry out high-resolution FUSE spectroscopy of the nuclear region of NGC 1068. The first set of spectra was obtainedwith a 3000 square aperture that collected all emission from the narrow-line region. The data reveal a strong broad O VI component of FWHM similar to 3500 km s(-1) and two narrow O VI lambda lambda 1031, 1037 components of similar to 350 km s(-1). The C III lambda 977 and N III lambda 991 emission lines in this spectrum can be fitted with a narrow component of FWHM similar to 1000 km s(-1) and a broad one of similar to 2500 km s(-1). Another set of seven spatially resolved spectra was made using a long slit of 1.25 x 20 at steps of similar to 1 along the axis of the emission-line cone. We find the following: (1) Major emission lines in the FUSE wavelength range consist of a broad and a narrow component. (2) There is a gradient in the velocity field for the narrow O VI component of similar to 200 km s(-1) from similar to 2 southwest of the nucleus to similar to 4 northeast. A similar pattern is also observed with the broad O VI component, with a gradient of similar to 3000 km s(-1). These are consistent with the HST STIS findings and suggest a biconical structure in which the velocity field is mainly radial outflow. (3) A major portion of the C III and N III line flux is produced in the compact core. They are therefore not effective temperature diagnostics for the conical region. (4) The best-fit UV continuum suggests virtually no reddening, and the He II I(lambda 1640)/I(lambda 1085) ratio suggests a consistently low extinction factor across the cone. At similar to 2 northeast of the nucleus there is a region characterized by (a) a strong Ly alpha flux but normal C IV flux, (b) a broad O VI line, and (c) a significantly enhanced C III flux.