Multiwavelength studies of the seyfert 1 galaxy NGC 7469 - I. Far UV observations with FUSE

We obtained far-ultraviolet spectra of the Seyfert 1 galaxy NGC 7469 using the Far Ultraviolet Spectroscopic Explorer on 1999 December 6. Our spectra cover the wavelength range 990-1187 Angstrom with a resolution of similar to0.05 Angstrom. We see broad emission lines of C III, N III, O VI, and He II as well as intrinsic absorption lines in the O VI lambdalambda1032; 1038 resonance doublet. The absorption arises in two distinct kinematic components at systemic velocities of -569 km s(-1) and -1898 km s(-1). Both components are very highly ionized - no significant Lybeta absorption is present. The higher blueshift component is not quite saturated, and it has a total O VI column density of 8 x 1014 cm(-2). It covers more than 90% of the continuum and broadline emission. The lower blueshift component is heavily saturated and covers only similar to50% of the continuum and broad-line emission. It too has a column density of 8 x 10(14) cm(-2), but this is less certain due to the high saturation. We set an upper limit of < 1.5 x 10(18) cm(-2) on the O VI column density of this component. Its line depth is consistent with coverage of only the continuum, and thus this component may lie interior to the broad emission-line gas. The component at - 569 km s(-1) has a velocity comparable to the high-ionization X-ray absorption lines seen in the XMM-Newton grating spectrum of NGC 7469, and photoionization models show that the observed column densities of O VI and H I are compatible with their formation in the same gas as that causing the X-ray absorption. The gas at - 1898 km s(-1) has lower ionization and column density, and no significant X-ray absorption is associated with it.