Search Publications
Evidence for 4.4 hour periodic dips in the X-ray flux from 4U 1755-33.
Parmar, A. N.; White, N. E.; Kahn, S. M. +3 more
The paper reports the discovery by the EXOSAT Observatory of three equally spaced dips in the flux from 4U 1755 - 33 that suggest the binary period of this system to be 4.4 hr. The duration of each dip is of order 30 minutes with considerable variability within each event on time scales between 30 and 600 s. The variations are spectrally independe…
The detection of X-rays from nova MUSCAE 1983 with the EXOSAT satellite.
Beuermann, K.; Krautter, J.; Oegelman, H.
Nova Muscae 1983, a fast classical nova, was discovered on January 18, 1983, by Liller (1983). The present investigation is concerned with a study of this star on the basis of X-ray observations which have been conducted with the low- and medium-energy detectors of the Exosat satellite on April 20, 1984. The measured data are combined with other m…
Evidence for an increasing 59-s period in the X-ray emission from Geminga
Caraveo, P. A.; Bignami, G. F.; Paul, J. A.
Einstein Observatory and Exosat X-ray data from 1E0630 + 178 reveal a ~50% periodic emission at >=59 s. This confirms the earlier SAS 2 and COS B findings on 2CG195 + 4 at E> 50 MeV, and provides the temporal signature for the identification of Geminga. The observations, spanning over a decade (1973-83), also suggest a very high positive per…
EXOSAT observations of GH 2215^-086 : detection of the X-ray pulse period
Watson, M. G.; McHardy, I. M.; Cook, M. C.
A 2.8 hr observation of the intermediate polar H2215 - 086 using the Exosat Medium Energy experiment has revealed a strong, quasi-sinusoidal modulation of the hard X-ray flux with a period (20.65 + or - 0.32 min) consistent with, and in phase with, that of the large amplitude optical variations. The detection of this hard X-ray modulation confirms…
Spectral and temporal features in bursts from 2S 1636-536 observed with EXOSAT.
Turner, M. J. L.; Breedon, L. M.
The well-known X-ray burster 2S 1636-536 (Nor X-1) was observed for 7 hr by the ME instrument on EXOSAT. During this time 7 bursts of unusual shape were detected. The bursts have similar profiles. The results suggest that each burst has two components with an initial helium thermonuclear flash triggering a stronger hydrogen flash; the ratio of con…
Feige 24 : wind : flare accretion by a hot DAZ1 degenerate.
Sion, E. M.; Starrfield, S. G.
Model stellar envelopes have been constructed in order to represent the outer layers of the hot DAZ white dwarf component of the spectroscopic binary Feige 24. The results of the calculations show that the metals, discovered by Dupree and Raymond (1983) should diffuse rapidly into the interior unless a continuous source of these elements is presen…
The EXOSAT imaging X-ray detectors.
Culhane, J. L.; Branduardi-Raymont, G.; Corbet, R. H. D. +3 more
Exosat observation of the candidate X-ray counterpart of Geminga
Caraveo, P. A.; Bignami, G. F.; Mereghetti, S. +2 more
During a search for X-ray counterparts of the COS B>=100 MeV γ-ray sources (see refs 1, 2), observations using the Einstein Observatory revealed a new X-ray source, 1E0630 + 178, inside the ~1/2 square degree error box of the γ-ray source 2GC195+4, `Geminga'3. On the basis of its interesting properties, this source has been proposed …
EXOSAT observation of 'Geminga'
Caraveo, P. A.; Bignami, G. F.
IE 0630 + 178, the X-ray source associated with the gamma-ray source Geminga (2CG195 + 04), has been observed by the EXOSAT satellite. The X-ray images, recorded by the channel-multiple-array instruments at the foci of the two low-energy telescopes equipped with different filters, show clearly the source. The flux value, computed from the count ra…
The European X-ray Astronomy Satellite EXOSAT: programme status.
Peacock, A.
The current status of the European X-ray Astronomy Satellite programme, EXOSAT, which includes the payload, spacecraft and ground segment are summarised. Details of the experiment performances and sensitivities are provided.