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EXOSAT observations of the Perseus cluster
Fabian, A. C.; Branduardi-Raymont, G.; Manzo, G. +3 more
EXOSAT CMA and GSPC observations of the Perseus Cluster of galaxies are reported. The soft X-ray image data confirm the earlier Einstein Observatory results in terms of the density distribution radially outward from NGC1275. We have used the GSPC spectral data at higher energies to study the strength of the X-ray continuum and of the Fe line emiss…
Detection of Iron Lines in the Persistent Emission of Some X-Ray Burst Sources Observed by EXOSAT
Hasinger, G.; Sztajno, M.; Truemper, J. +1 more
We have observed the X-ray burst sources 4U1728-33 and 4U1813-14 with the ME detectors aboard EXOSAT, and present here results of a spectral analysis of their persistent emissions. For both sources the data can be well fitted by a double blackbody continuum and a Gaussian emission line. The two spectral components can be interpreted in terms of a …
Studies of hot B subdwarfs. II. Energy distributions of three bright sdB/sdOB stars in the 950-5500 A range.
Veilleux, S.; Fontaine, G.; Wesemael, F. +2 more
Voyager ultraviolet spectrometer observations of the subdwarf B or OB stars HD 205805, UV 1758+36 and Feige 66 are presented. All three objects display the H I Layman series in absorption. These observations are combined with low dispersion IUE spectrophotometry and with Stromgren photometry to construct virtually complete energy distributions, wh…
IUE data analysis : radial velocities from line coincidence statistics.
Bord, D. J.; Davidson, J. P.
The authors have employed the method of wavelength coincidence statistics (WCS) to determine radial velocities from International Ultraviolet Explorer (IUE) satellite data for several chemically peculiar stars. By repeatedly carrying out the entire WCS procedure with a sequence of radial velocities, the authors demonstrate that significance-weight…
X-ray observations of Vela-X
Smith, A.; Zimmermann, H. U.
Exosat ME observations of the Vela-X region are presented. It is found that the 2-10 keV emission is divided into two components. One is associated with the rulsar but is probably extended by 10-20 arc minutes, the other is associated with the Vela-X radio nebula and is probably more extended (≈ 1 degree). The Vela-X component is softer than the p…
An EXOSAT observation of the peculiar X-ray binary 2S 0921-630 during optical eclipse
Branduardi-Raymont, G.; Mason, K. O.; Cordova, F. A. +1 more
An x-ray observation of 2S 0921-630 has been made coincident with the time of optical eclipse of this 9-day binary. No significant reduction in X-ray flux is measured. This can be explained if the binary orbit is viewed almost exactly edge-on, so that the central X-ray emitting star is obscured by the accretion disk from direct view. The X-rays th…
Cos-B Gamma-Ray Sources and Interstellar Gas
Caraveo, P. A.; Bignami, G. F.; Strong, A. W. +8 more
Of the gamma-radiation observed above 100 MeV only a few percent is due to the catalogued sources which are viewed against intense background mission from the Galactic plane. There has been considerable recent success in modelling the Galactic plane emission as the interactions of cosmic rays with atomic and molecular interstellar gas; Bloemen, et…
Cygnus X-3 not Seen at High-Energy Gamma-Rays
Hermsen, W.
The ESA satellite COS-B viewed the Cyg-X region 7 times between November 1975 and March 1982. A search for periodic gamma-ray emission (E > 70 MeV) from Cyg X-3 at the characteristic ∼4.8 h period did not reveal the source. Combining all observations, the 2σ upperlimit (E > 70 MeV) on the flux for the phase interval in which X-ray emission h…
X-Ray Observations of Active Chromosphere Stars
Bedford, D. K.; Eyles, C. J.; Elliott, K. H.
HD3196 = 13 Cet α, HD30495 = 58 Eri and HD32918 have been detected as new late-type soft X-ray sources. HD32918 is a member of the FK Com class.
IUE observations of the RS CVn systems Z Her, TY Pyx and HD 155555.
Fernandez-Figueroa, M. J.; de Castro, E.; Gimenez, A.
Short wavelength (λλ1150 - 1950 Å) low resolution ultraviolet spectra of three RS CVn regular-period binary systems, obtained with the IUE satellite, have been examined. Newly observed spectra were compared with those retrieved from the IUE data bank. The surface fluxes of chromospheric and transition region lines were obtained and are briefly dis…