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Steps toward Determination of the Size and Structure of the Broad-Line Region in Active Galactic Nuclei. IX. Ultraviolet Observations of Fairall 9

Shull, J. M.; Malkan, M. A.; Martin, P. G. +53 more

An 8 month monitoring campaign on the Seyfert 1 galaxy Fairall 9 has been conducted with the International Ultraviolet Explorer in an attempt to obtain reliable estimates of continuum-continuum and continuum-emission-line delays for a high-luminosity active galactic nucleus (AGN). While the results of this campaign are more ambiguous than those of…

Steps toward Determination of the Size and Structure of the Broad-Line Region in Active Galactic Nuclei. XI. Intensive Monitoring of the Ultraviolet Spectrum of NGC 7469

Shull, J. M.; Malkan, M. A.; Nandra, K. +54 more

From 1996 June 10 to July 29, the International Ultraviolet Explorer monitored the Seyfert 1 galaxy NGC 7469 continuously in an attempt to measure time delays between the continuum and emission-line fluxes. From the time delays, one can estimate the size of the region dominating the production of the UV emission lines in this source. We find the s…

The Spectrum of the Planetary Nebula NGC 6884

Feibelman, Walter A.; Hyung, Siek; Aller, Lawrence H.

The bright, compact, moderately high-excitation planetary nebula, NGC 6884 (Perek-Kohoutek 82 +07°1) has a rich spectrum promising good diagnostics and offering a good target for the Hamilton Echelle Spectrograph at Lick Observatory. We combine International Ultraviolet Explorer (IUE), near-UV, visual, and IR data to obtain N(ion)/N(H⁺)…

The IUE Spectrum of the ``O VI Sequence'' Planetary Nebula IC 2003

Feibelman, Walter A.

We present archival low- and high-dispersion, as well as new SWP high-dispersion, IUE data of the ``O VI sequence'' planetary nebula IC 2003 that has not been studied extensively in the UV. Contrary to earlier UV studies, IC 2003 shows a rich spectrum of stellar and nebular emission lines. Nearly 60 new emission line fluxes are presented for He II…

The Greatly Expanded IUE Spectrum of the Planetary Nebula NGC 2371-2 and Its Central Star

Feibelman, Walter A.

Early IUE low-dispersion SWP and LWR spectra have been reexamined by means of refined current data reduction routines. These spectra contain much more information than was reported in 1981. A high-dispersion SWP spectrum was obtained in 1994 from which more than 80 emission and absorption features were identified, and log N_e = 3.0 +/- 0…