Search Publications
Combined Ultraviolet and Optical Spectra of 48 Low-Redshift QSOs and the Relation of the Continuum and Emission-Line Properties
Corbin, Michael R.; Boroson, Todd A.
We present combined ultraviolet and optical spectra of 48 QSOs and Seyfert 1 galaxies in the redshift range 0.034-0.774. The UV spectra were obtained non-simultaneously with the optical and are derived from archival Hubble Space Telescope (HST) Faint Object Spectrograph and International Ultraviolet Explorer (IUE) observations. The sample consists…
A Multiwavelength Catalog of Seyfert 2 Galaxies Observed in the 2--10 keV Energy Band
Malaguti, G.; Bassani, L.; Polletta, M. +2 more
This paper is a catalog of Seyfert 2 galaxies observed in the 2-10 keV band (339 flux entries). In total, it contains data on 150 objects; for 76 objects, a positive detection is reported, while for the remaining sources, 2 σ upper limits to the X-ray emission are given. Most of the data have been collected from the literature over a period starti…
Ultra--Steep-Spectrum Radio Sources. II. Radio, Infrared, Optical, and HST Imaging of High-Redshift 4C Objects
Huang, J. -S.; Chambers, K. C.; Miley, G. K. +3 more
We present radio, infrared, optical, and HST imaging data on eight high-redshift (z > 2) ultra-steep-spectrum 4C radio sources. The radio polarization morphologies are highly asymmetric, indicating large rotation measures across the objects. The optical morphologies are all aligned with the radio axis. The multicolor images show strong asymmetr…
An Atlas of Hubble Space Telescope Ultraviolet Images of Nearby Galaxies
Filippenko, Alexei V.; Ho, Luis C.; Maoz, Dan +3 more
We present an atlas of UV (~2300 A) images, obtained with the Hubble Space Telescope (HST) Faint Object Camera, of the central 22" x 22" of 110 galaxies. The observed galaxies are an unbiased selection constituting about one-half of a complete sample of all large (D > 6') and nearby (V < 2000 km s^-1^) galaxies. This is the first extensive U…
Cepheid Calibration of the Peak Brightness of Type IA Supernovae. VI. SN 1960F in NGC 4496A
Panagia, N.; Saha, A.; Labhardt, Lukas +3 more
Cepheid variables have been found in the SBcII galaxy NGC 4496A, parent to the Type Ia supernova 1960F. Of the 130 variables discovered with the Hubble Space Telescope (HST) over a 70 day observing internal from 1994 June to August, comprising 17 epochs in the F555W band and four epochs in the F814W band, 95 are bona fide Cepheids. The periods ran…
Hubble Space Telescope Observations of Planetary Nebulae in the Magellanic Clouds. III. Ultraviolet Spectroscopy Using the Faint Object Spectrograph
Ford, H. C.; Harrington, J. P.; Wood, P. R. +6 more
Ultraviolet grating spectra (λλ1150-2300) of planetary nebulae in the Magellanic Clouds, obtained with the Faint Object Spectrograph (FOS) on the Hubble Space Telescope (HST), are used to identify and measure nebular emission lines and continua, and in one case to detect the stellar wind of the central star. Eight nebulae are observed in the Large…
Correlation of Ultraviolet and Radio Flux in Three Active Galactic Nuclei
Shukla, Hemant; Stoner, Ronald E.
We report the results of a search for correlations between the time- variable ultraviolet (UV) and the radio flux in three AGNs, viz., 3C 273, 3C 120, and PKS 2155-304. Data from 1984 to present were used. UV data from the short-wave IUE camera were downloaded from the IUE Regional Data Analysis Facility and the National Space Science Data Center …
Mg Emission from Hybrid-Chromosphere Stars: 1.5 Decades of Chromospheric Variability Monitoring
Ayres, Thomas R.; Bennett, Philip D.; Brown, Alexander +2 more
We present an analysis of the available long-wavelength, high-dispersion spectra of seven hybrid-chromosphere stars obtained with the International Ultraviolet Explorer between 1978 and 1993. Our investigation of the variability of the Mg II h and k resonance doublet demonstrates that the emission- line fluxes are not rotationally modulated with t…
Far-Ultraviolet Stellar Photometry: Fields Centered on rho Ophiuchi and the Galactic Center
Schmidt, Edward G.; Carruthers, George R.
Far-ultraviolet photometry is presented for 121 objects in a 20 diameter field centered on ρ Oph and for 649 objects in a field covering the Galactic center. Broadband magnitudes with effective wavelengths of 1375 Å and 1781 Å are given. The Galactic center field overlaps two fields which were discussed in an earlier paper. Eighty- eight percent o…
Steps toward Determination of the Size and Structure of the Broad-Line Region in Active Galactic Nuclei. VIII. an Intensive HST, IUE, and Ground-based Study of NGC 5548
Veilleux, S.; Shull, J. M.; Malkan, M. A. +109 more
We present the data and initial results from a combined HST/IUE/groundbased spectroscopic monitoring campaign on the Seyfert 1 galaxy NGC 5548 that was undertaken in order to address questions that require both higher temporal resolution and higher signal-to-noise ratios than were obtained in our previous multiwavelength monitoring of this galaxy …