Search Publications
Atlas of Quasar Energy Distributions
Elvis, Martin; Wilkes, Belinda J.; McDowell, Jonathan C. +6 more
We present an atlas of the spectral energy distributions (SEDs) of normal, nonblazar, quasars over the whole available range (radio to 10 keV X-rays) of the electromagnetic spectrum. The primary (UVSX) sample includes 47 quasars for which the spectral energy distributions include X-ray spectral indices and UV data. Of these, 29 are radio quiet, an…
An IUE Survey of Interstellar H i LY alpha Absorption. I. Column Densities
Savage, Blair D.; Diplas, Athanassios
We measure Galactic interstellar neutral hydrogen column densities by analyzing archival interstellar Ly alpha absorption line data toward 554 B2 and hotter stars observed at high resolution with the IUE satellite. This study more than doubles the number of lines of sight with measures of N(H I) based on Ly alpha. We have included the scattered li…
A Compilation of Electronic Transitions in the CO Molecule and the Interpretation of Some Puzzling Interstellar Absorption Features
Morton, Donald C.; Noreau, Louis
This compilation lists wavenumbers, wavelengths, and oscillator strengths for 1589 electronic transitions of (12)C(16)O, (13)C(16)O, (12)C(18)O, and (13)C(18)O between 1000 and 1545 A. These are the transitions from J double prime = 0 to 6 and v double prime = 0 of the ground term which are most likely to appear as interstellar absorption lines in…
Density Contrast Shell Models for the Planetary Nebula IC 2165
Hyung, S.
Since planetary nebulae are spatially extended sources, measurements of individual line fluxes may pertain to different areas of their images. Photoelectric or infrared observations of the strongest lines may embrace the entire image; International Ultraviolet Explorer (IUE) observations involve an elliptical aperture, 10 sec x 23 sec; while a spe…
The X-Ray Spectra of Blazars: Analysis of the Complete EXOSAT Archive
Giommi, Paolo; Barr, Paul; Sambruna, Rita M. +3 more
We analyzed the 0.1-10 keV spectra of 26 blazars (21 BL Lac objects and 5 highly polarized quasars), on the basis of 93 exposures taken from the EXOSAT archives. Fits were performed first with a single power-law model. Indications are found that better fits can be obtained with models where the slope steepens at higher energies. We therefore consi…
An Atlas of Ultraviolet P Cygni Profiles
Snow, Theodore P.; Lamers, Henny J. G. L. M.; Lindholm, Douglas M. +1 more
We have selected spectra of 232 stars from the International Ultraviolet Explorer (IUE) archives for inclusion in an atlas intended for various uses but tailored especially for the study of stellar winds. The atlas covers the range in spectral types from O3 to F8. The full atlas covers the reduced and normalized high resolution spectra from the IU…
High-Energy Spectra of Active Galactic Nuclei. I. The Catalog
Malaguti, G.; Bassani, L.; Caroli, E.
This paper presents a catalog of high-energy spectra (E >= 0.01 keV) of active galactic nuclei (AGNs). The catalog contains 209 objects (140 Seyfert galaxies, 65 quasars, and 4 objects otherwise classified), for a total of 1030 spectra. Most of the data have been collected from the literature over a period spanning more than 20 yr starting from…
Hubble Space Telescope Observations of Synchrotron Jets
Sparks, W. B.; Macchetto, F.; Biretta, J. A.
The Hubble Space Telescope for the first time enables optical and UV images of jets to be obtained with spatial resolution comparable to radio interferometric techniques. Because synchrotron emission at these wavelengths is a diagnostic of particles several orders of magnitude higher in energy and correspondingly shorter in lifetime than those pro…
Jupiter Radio Bursts and Particle Acceleration
Desch, Michael D.
Particle acceleration processes are important in understanding many of the Jovian radio and plasma wave emissions. However, except for the high-energy electrons that generate synchrotron emission following inward diffusion from the outer magnetosphere, acceleration processes in Jupiter's magnetosphere and between Jupiter and Io are poorly understo…
Gamma-Ray Pulsar Studies with COMPTEL
Strong, A. W.; Grenier, I. A.; Diehl, R. +10 more
Since the launch of the Compton Gamma-Ray Observatory (CGRO) the number of detected gamma-ray pulsars increased from two to six. COMPTEL, on-board CGRO and sensitive to gamma-rays with energies between approximately 0.7 and 30 MeV, detected three of these unambiguously. The classical Crab and Vela pulsars have been observed on several occasions an…