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The Near-Ultraviolet Spectrum of Markarian 205
Jenkins, Edward B.; Schneider, Donald P.; Jannuzi, Buell T. +2 more
We report measurements of the absorption and of the emission lines between 1600 and 3200 A in the spectrum of the nearby AGN Markarian 205 (z = 0.071), which lies at a projected distance of 3 kpc (H_0_= 100 km s^-1^) from the nucleus of the nearby barred spiral galaxy NGC 4319 (z = 0.0047). The results were obtained using high-resolution (R = 1300…
Ultraviolet Imaging Telescope Observations of the Cygnus Loop
Jenkins, Edward B.; Gull, Theodore R.; Cheng, Kwang-Ping +8 more
Attention is given to UV images of a 40-arcmin field in the northeast part of the Cygnus Loop made by the Ultraviolet Imaging Telescope (UIT) during the Astro-1 mission in December 1990. The longest FUV (B5) exposure is compared with ground-based and X-ray observations and with models. It is inferred from SNR shock models that C IV 1550 A dominate…
Comparing Restored HST and VLA Imagery of R Aquarii
Hollis, J. M.; Yusef-Zadeh, F.; Dorband, J. E.
The maximum entropy method is applied to Hubble Space Telescope data taken of the R Aquarii binary system and its jet with the Faint Object Camera in order to restore an image in forbidden O III at 5007 A plagued by spherical aberration and detector saturation. These results are compared with 2-cm radio continuum imagery taken with the Very Large …
The Diffuse Interstellar Cloud toward HD 179406 (20 Aquilae)
Snow, Theodore P.; Black, John H.; Hanson, Margaret M.
An analysis of the diffuse interstellar cloud complex in front of HD 179406 (20 Aql) is presented. Along this sight line, multispectral absortion- and emission-line studies have uncovered at least three distinct velocity components due to individual clouds. A dominant velocity component is seen in both the absorption and emission-line data sets at…
Ulysses Radio Occultation Observations of the Io Plasma Torus During the Jupiter Encounter
Bird, M. K.; Asmar, S. W.; Volland, H. +4 more
Radio signals from Ulysses were used to probe the lo plasma torus (IPT) shortly after the spacecraft's closest approach to Jupiter. The frequencies of the two downlinks at S-band (2.3 gigahertz) and X-band (8.4 gigahertz) were recorded, differenced, and integrated in order to derive the columnar electron density of the IPT. The measurements agree …
The Colorado IUE Active Galaxy Survey. I. Blazars
Shull, J. M.; Kinney, Anne; Edelson, Rick +2 more
This paper presents consistently reduced ultraviolet continuum flux densities and spectral indices derived from all 499 usable archived IUE observations of blazars made through mid-1991. The extraction of one-dimensional spectra and the measurement of spectral parameters are discussed. A detailed error analysis is presented, including a discussion…
The Ultraviolet-bright Stars of Omega Centauri, M3, and M13
O'Connell, Robert W.; Hill, Robert S.; Bohlin, Ralph C. +7 more
Two new UV-bright stars detected within 2 arcmin of the center of Omega Cen are spectroscopically investigated with the short-wavelength spectrograph of the IUE. The IUE spectra of the UV-bright stars UIT-1 and UIT-2 in the core of Omega Cen superficially resemble those of Population I mid-B stars. The absorption lines of the core UV-bright stars …
Inner Shell of Optically Thin Gas in Active Galactic Nuclei
Zheng, Wei
The Lyα and Balmer line profiles in more than 50 Seyfert 1 galaxies and QSOs are studied. Approximately 60% of the objects show similar profiles, 25% show smaller FWHM of Hβ or Hα. In five objects the Lyα profiles have stronger wings than the Balmer lines. The Lyα/Balmer ratio increases along both wings, suggesting an inner envelope of a very broa…
Coordinated Ginga, IUE, and VLA Observations of Stellar Activity in sigma 2 Coronae Borealis
Walter, F.; Vilhu, O.; Stern, R. A. +5 more
Observations of the active cool star binary system Sigma(2) Corona Borealis with the Large Area Counters on the Ginga X-ray satellite over 2.5 d, or about two orbital periods, are reported. Throughout the observations, Sigma(2) CrB exhibited X-ray variability on time scales ranging from tens of minutes to hours. The X-ray light curve shows evidenc…
H 0414+009 - an X-ray bright BL Lac with a radio tail in a distant cluster of galaxies.
Abraham, R. G.; George, I. M.; McHardy, I. M. +2 more
VLA observations of the X-ray selected BL Lac H0414+009 at 6, 20 and 90 cm show that it has a steep-spectrum (α~1; f_v_ is proportional to v^-α^) radio tail. The tail extends ~40 arcsec from the core, in a gentle curve. There is no evidence of extended emission on the opposite side of the core. This is by far the clearest example of a single-sided…