Search Publications
The X-Ray to Infrared Energy Distribution of the Quasar PG 0026+129
Maraschi, L.; Tanzi, E. G.; Chiappetti, L. +4 more
PG 0026+129 was observed with EXOSAT in 1983 and 1984. No variation between the two epochs was detected. The energy distribution from 0.2 to 6 keV is well fitted by a power law of energy index α = 1.06 +/- 0.25 and with Galactic absorption. Quasi-simultaneous spectrophotometry in the UV and optical range, together with near-infrared photometry was…
IUE Observations of the Dwarf Nova BV Centauri
Hassall, B. J. M.; Wade, Richard A.; Williger, G. +1 more
The IUE observations of the dwarf nova BV Cen in quiescence are summarized. The reprocessed spectra from January 1979 are analyzed to show that the maximum temperature of the white dwarf primary star, based on its brightness at 1375 A, ranges from 42,000 to about 125,000 K depending upon the adopted values of interstellar reddening, the mass of th…
An EXOSAT Observation of CTB 80
Parmar, A. N.; White, N. E.; Angelini, L. +2 more
The results of an EXOSAT observation of the Crab-like supernova remnant CTB 80 are presented. The 0.05-6 keV X-ray spectrum is well fitted by a power law with an energy index of 0.9, similar to that of other Crab-like remnants. This spectral measurement differs from an earlier result from an Einstein observation where a much steeper index was repo…
Massive Star-Formation Regions in the Magellanic Clouds
Thompson, I. B.; Hutchings, J. B.
We present optical and UV spectroscopy of stars from six compact, luminous groups or clusters in the SMC and LMC. The groups are characterized by high concentrations of nebulosity or starlight confined to areas smaller than 30" on a side, in which some stars can be resolved. The spectra and fluxes are used to derive luminosities and effective temp…
Phase-resolved IUE Observations of AM Herculis System E1405-451
Nousek, J. A.; Takalo, L. O.
The authors report the first phase-resolved IUE observations of the AM Herculis system E1405-451. The spectra show bright emission lines from N V, C IV, and He II, whose centroids vary drastically during the 101.5 minute period. The radial velocities measured from the line centroids show a sinusoidal variation with a semi-amplitude of 300 km s
IUE--IRAS Studies of the Infrared Cirrus
Shull, J. Michael; van Steenberg, Michael E.
The authors have studied correlations of IRAS infrared cirrus fluxes with interstellar parameters toward 256 OB stars observed with IUE. The 60 and 100 µm fluxes correlate with N(H I), n, E(B - V), spectral type, vertical distance from the Galactic plane, and general UV illumination. No correlation was found with abundances of Si, Mn, Fe, S,…
EXOSAT Observations of the Hot Gas in the A1060 Cluster of Galaxies
Singh, K. P.; Westergaard, N. J.; Schnopper, H. W.
We have used the EXOSAT Observatory to map and to obtain the X-ray spectrum of the hot gas in the A1060 cluster of galaxies. The density and temperature profiles of the intracluster gas have been determined by spherical deprojection of the X-ray surface brightness distribution obtained. We assume hydrostatic equilibrium and a cluster gravitational…
The Extended Atmosphere of lambda Pavonis at the Time of the Emergence of H-Emissions from Minimum Intensity
Cidale, Lydia; Sahade, Jorge; Kondo, Yoji +2 more
A study of the Be star λ Pavonis, particularly of the changes in the Balmer discontinuity in the interval 1949 - 1982, is presented. Nearly simultaneous observations carried out with the ESO 1.5 m reflector at La Silla and with the IUE satellite correspond to an epoch when the H emission is starting to increase in intensity immediately after havin…