Multiwavelength studies of the Seyfert 1 galaxy NGC 7469 I. Far UV observations with FUSE
Abstract
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 Å with a resolution of ~ 0.05 Å. 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 lambda lambda1032 ,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 broad-line emission. The lower blueshift component is heavily saturated and covers only ~ 50% of the continuum and broad-line emission. It too has a column density of 8 x 1014 cm-2, but this is less certain due to the high saturation. We set an upper limit of <1.5 x 1018 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.
- Publication:
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Astronomy and Astrophysics
- Pub Date:
- May 2003
- DOI:
- 10.1051/0004-6361:20030258
- arXiv:
- arXiv:astro-ph/0302552
- Bibcode:
- 2003A&A...403..473K
- Keywords:
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- galaxies: active;
- galaxies: individual (NGC 7469);
- galaxies: quasars: absorption lines;
- galaxies: Seyfert;
- ultraviolet: galaxies;
- X-rays: galaxies;
- Astrophysics
- E-Print:
- To appear in Astronomy &