Intrinsic Absorption in the Spectrum of NGC 7469: SimultaneousChandra,FUSE, and STIS Observations

We present simultaneous X-ray, far-ultraviolet, and near-ultraviolet spectraof the Seyfert 1 galaxy NGC 7469 obtained with the Chandra X-Ray Observatory,the Far Ultraviolet Spectroscopic Explorer, and the Space Telescope ImagingSpectrograph on the Hubble Space Telescope. Previous non-simultaneousobservations of this galaxy found two distinct UV absorption components, at-560 and -1900 km/s, with the former as the likely counterpart of the X-rayabsorber. We confirm these two absorption components in our new UVobservations, in which we detect prominent O VI, Ly alpha, N V, and C IVabsorption. In our Chandra spectrum we detect O VIII emission, but nosignificant O VIII or O VII absorption. We also detect a prominent Fe K alphaemission line in the Chandra spectrum, as well as absorption due tohydrogen-like and helium-like neon, magnesium, and silicon at velocitiesconsistent with the -560 km/s UV absorber. The FUSE and STIS data reveal thatthe H I and C IV column densities in this UV- and X-ray- absorbing componenthave increased over time, as the UV continuum flux decreased. We use measured HI, N V, C IV, and O VI column densities to model the photoionization state ofboth absorbers self-consistently. We confirm the general physical picture ofthe outflow in which the low velocity component is a highly ionized, highdensity absorber with a total column density of 10^20 cm^-2, located near thebroad emission line region, although due to measurable columns of N V and C IV,we assign it a somewhat smaller ionization parameter than found previously,U~1. The high velocity UV component is of lower density, log N=18.6, and likelyresides farther from the central engine as we find its ionization parameter tobe U=0.08.Comment: Minor correction to abstract; STScI eprint #1683; 50 pages, incl. 19 figures, 4 tables; Accepted to Ap