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EXOSAT 2 10 KeV observations of M87 and the Virgo cluster
Smith, A.; Stewart, G.
A series of observations of the Virgo cluster of galaxies with the Medium Energy experiment on board EXOSAT are presented. These take the form of two orthogonal scans meeting at M87. The observed count rates have been compared with those obtained with the IPC on board the EINSTEIN observatory and are found to be consistent with the the IPC surface…
EXOSAT Le-Canis Observations of the VELA Supernova Remnant
Smith, A.; Zimmermann, H. -U.
Presented here are Exosat LE1-CMA images of fields in the Vela SNR. Soft X-ray emission is observed in the north of the remnant indicating a filamentry structure. No X-ray emission was seen in two fields to the west and south-west which have optical filaments but were not studied by Einstein. The Vela pulsar is observed and is significantly broade…
EXOSAT Observations of the Iron Line Emission of HERCULES-X-1 during a 35-DAY Cycle
Pietsch, W.; Kahabka, P.; Truemper, J. +2 more
In March/April 1984 eleven EXOSAT observations of Her X-1 were performed sampling a full 35 day cycle. Spectral analysis of the ME and GSPC data shows that the iron line emission is present during all phases. During the main-on state we see an iron line at 6.65 ± 0.07 keV with a FWHM of 1 2 keV and an equivalent width of 300 to 400 eV. The high re…
CYG X-3: not Seen in High-Energy Gamma Rays by Cos-B
Caraveo, P. A.; Bignami, G. F.; Strong, A. W. +7 more
COS-B had Cyg X-3 within its field of view during 7 observation periods between 1975 and 1982 for in total approximately 300 days. In the skymaps (70 meV E 5000 meV) of the Cyg-X region produced for each of these observations and in the summed map, a broad complex structure is visible in the region 72 deg approximately less than 1 approximately le…
The nature of Weinberger-12.
Feibelman, W. A.; Kaler, J. B.
From IUE spectra of its central star, the authors conclude that Weinberger-12 is a small H II region, and not a planetary nebula. The star is substantially reddened with a color excess of 0m.75, is most likely a B0.5 - B1 giant or subgiant about three kpc distant, and possibly belongs to the Cas OB2 association.
Properties and Nature of Be Stars. 12. The UV Line Spectrum of KX And - Is There a Hot Primary?
Štefl, S.
Seven high-resolution IUE spectrograms of the Be star KX And were investigated by the standard method of comparison of the observed and theoretical spectra. The whole ultraviolet line spectrum can be described quite well by a model spectrum, corresponding to Kurucz's model with Teff = 9000 - 10000K and log g = 2.00. A detailed identific…
A High Quality Low State Observation of CIRCINUS-X-1
Tennant, A. F.
Cir X-1 was extremely faint when we observed it with EXOSAT. The light curve clearly shows the source in two states; a faint variable state and a very faint but more constant state. The spectrum is very complicated but clearly shows the existence of an iron line.
HR 5637 : the unveiling of a binary.
Cottrell, P. L.; Ake, T. B., III; Noordanus, B.
HR 5637, previously classified as G1/3 Ib/II but considered composite by Bidelman and MacConnell, has been examined both photometrically and spectroscopically. The spectroscopic observations spanned the wavelength interval 1000-7000 A. Using these data in various combinations, the star is shown to be a binary with components of G2-5Ib and B8 V, wi…
Is cygnus X-3 a low-mass X-ray binary?
van der Klis, M.; Jansen, F.
We present examples of the quasi-periodic variations in the X-ray flux of Cyg X-3 which we have recently found during observations of this source with EXOSAT. Amplitudes and periods of the variations range from 5% to 20% of the total flux and from 50 to 1500 s, respectively. Our tentative interpretation of these quasi-periodicities, the occurrence…
EXOSAT Observations of the Contact Binary Vw-Cephei
Heise, John; Vilhu, Osmi
EXOSAT observations of the contact binary VW Cephei on 19th March 1984 are presented. The L1-telescope with CMA+thick Lexan filter was used. The observations cover one orbital revolution showing an asymmetrical X-ray light curve. This can be modelled by an active neck, connecting the two stars, and with enhanced coronal regions on the primary star…