Search Publications
A Hubble Space Telescope Imaging Survey of Nearby Active Galactic Nuclei
Gorjian, Varoujan; Malkan, Matthew A.; Tam, Raymond
We have obtained WFPC2 images of 256 of the nearest (z <= 0.035) Seyfert 1, Seyfert 2, and starburst galaxies. Our 500 s broadband (F606W) exposures reveal much fine-scale structure in the centers of these galaxies, including dust lanes and patches, bars, rings, wisps, and filaments, and tidal features such as warps and tails. Most of this fine…
Temperature Dependence of Ultraviolet Line Average Doppler Shifts in the Quiet Sun
Chae, J.; Yun, H. S.; Poland, A. I.
The existence of prevailing redshifts in the UV lines formed in the solar transition region raises an important question concerning its physical origin and its role in the mass and energy balance of the outer solar atmosphere. A series of UV spectral lines observed by SUMER has been analyzed to obtain the spatial average of Doppler shifts in the q…
The Hubble Space Telescope Quasar Absorption Line Key Project. XIII. A Census of Absorption-Line Systems at Low Redshift
Turnshek, David A.; Schneider, Donald P.; Savage, Blair D. +9 more
We present a catalog of absorption lines obtained from the analysis of the ultraviolet spectra of 66 quasars. The data were acquired with the Faint Object Spectrograph of the Hubble Space Telescope (HST) as part of the Quasar Absorption Line Survey, a Key Project for the first four cycles of HST observations. This is the third of a series of catal…
Solar Active Region and Quiet-Sun Extreme-Ultraviolet Spectra from SERTS-95
Brosius, Jeffrey W.; Thomas, Roger J.; Davila, Joseph M.
Goddard Space Flight Center's Solar EUV Rocket Telescope and Spectrograph was flown on 1995 May 15 (SERTS-95), carrying a multilayer-coated toroidal diffraction grating that enhanced the instrumental sensitivity in its second-order wave band (171-225 Å). Spectra and spectroheliograms of NOAA active region 7870 (N09 W22) were obtained in this wave …
A High-Dispersion Spectroscopic Survey of the Hot White Dwarfs: The IUE NEWSIPS SWP Echelle Data Set
Barstow, M. A.; Sion, E. M.; Holberg, J. B.
This paper summarizes the results obtained from a comprehensive analysis of all of the SWP echelle spectra of the white dwarf stars contained in the IUE Final Archive. A total of 209 NEWSIPS spectra of 55 degenerate stars of various types have been systematically reduced and analyzed. These include, in addition to conventional white dwarfs, severa…
High-Resolution Observations of the Solar Hydrogen Lyman Lines in the Quiet Sun with the SUMER Instrument on SOHO
Wilhelm, K.; Mariska, J. T.; Warren, H. P.
We present high-resolution observations of the higher H Lyman series lines taken with the Solar Ultraviolet Measurements of Emitted Radiation (SUMER) experiment flown on the Solar and Heliospheric Observatory (SOHO) spacecraft. We have used systematic observations extending from disk center to the solar limb to compute average profiles for represe…
Ultraviolet and Optical Studies of Binaries with Luminous Cool Primaries and Hot Companions. V. The Entire IUE Sample
Parsons, Sidney B.; Ake, Thomas B.
We have obtained or retrieved IUE spectra for over 100 middle- and late-type giant and supergiant stars whose spectra indicate the presence of a hot component earlier than type F2. The hot companions are classified accurately by temperature class from their far-UV spectra. The interstellar extinction of each system and the relative luminosities of…
The Ultraviolet Continuum Emission of Radio Galaxies. I. Description of Sources from the Hubble Space Telescope Archives
Baum, Stefi A.; Zirbel, Esther L.
This paper describes the UV continuum radiation in the range from 1400 to 3700 Å of radio galaxies. The analysis is deferred to the next paper in this series. The sample of radio galaxies was compiled by searching the Hubble Space Telescope (HST) archives for images taken with the Faint Object Camera (FOC) prior to 1993. Altogether the sample cons…
Gamma-Ray Burst Arrival Time Localizations: Simultaneous Observations by Pioneer Venus Orbiter, Compton Gamma-Ray Observatory, and ULYSSES
Hurley, K. C.; Fishman, G. J.; Kouveliotou, C. +9 more
Between the Compton Gamma Ray Observatory (CGRO) launch in 1991 April and the Pioneer Venus Orbiter (PVO) demise in 1992 October, concurrent coverage by CGRO, PVO, and Ulysses was obtained for several hundred gamma-ray bursts (GRBs). Although most of these were below the PVO and Ulysses thresholds, 37 were positively detected by all three spacecra…
Gamma-Ray Burst Counterparts: Optical Data
Schaefer, Bradley E.; Cline, Thomas L.; Hurley, Kevin C. +1 more
The surest solution of the gamma-ray burst (GRB) mystery is to find an unambiguous low-energy quiescent counterpart. To this end, we have intensively searched within the smallest GRB error boxes for any counterpart candidates. This paper reports on 255 hr of exposure with ground-based telescopes since 1981. We report our results in the U, B, V, R.…