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The spectral signature of the cooling flow in Abell 478.
Fabian, A. C.; Edge, A. C.; Johnstone, R. M. +1 more
We present X-ray spectra of Abell 478 taken with the Ginga LAC and with the Einstein SSS. The LAC data set an upper limit of ~440 M_sun_ yr^-1^ on the mass deposition rate throughout the whole cluster if a value for the galactic absorption based on 21-cm observations of H I is adopted. The SSS data strongly require an absorbing column density well…
Radio-loud and radio-quiet quasars observed by EXOSAT.
Saxton, R. D.; Turner, M. J. L.; Stewart, G. C. +2 more
We present results from the spectral analysis of EXOSAT data on 31 quasars, 18 radio-loud and 13 radio-quiet. Simple power-law models with fixed (Galactic) absorption give acceptable fits to the spectra obtained in the 2-10 keV band. Using the results from these fits we have compared the distributions of spectral indices α for the radio-loud and r…
The EXOSAT obseravtions of SS Cygni.
Watson, M. G.; Jones, M. H.
A series of nine observations of SS Cygni made using Exosat between 1983 November and 1984 September are presented. Distinct soft amd hard X-ray emitting components were spectrally resolved by the LE and ME instruments, respectively. In quiescence the source shows hard X-ray emission with a 2-10 keV luminosity of 1.2 x 10 exp 33 (d/200 pc)-squared…
GINGA and EXOSAT observations of the Perseus cluster of galaxies.
Fabian, A. C.; Allen, S. W.; Edge, A. C. +2 more
We report observations of the Perseus cluster of galaxies made using the Ginga and EXOSAT satellites. Our results from Ginga indicate that the region around the centrally dominant galaxy NGC 1275 is well described by a model incorporating emission from an isothermal, diffuse plasma of temperature ~6.3 keV, metal abundance ~ 0.4 solar, a cooling fl…
Models for the remnants of recurrent novae - III. Comparison with the X-ray observations of RS Ophiuchi (1985).
Bode, M. F.; O'Brien, T. J.; Kahn, F. D.
The X-ray emission predicted by a model for the interaction of ejecta with a circumstellar medium is compared to Exosat observations of the 1985 outburst of the recurrent nova RS Ophiuchi. The model parameters are constrained by fitting the predicted spectrum to the first X-ray observation, made 55 days after the outburst, and are found to be cons…
H 0414+009 - an X-ray bright BL Lac with a radio tail in a distant cluster of galaxies.
Abraham, R. G.; George, I. M.; McHardy, I. M. +2 more
VLA observations of the X-ray selected BL Lac H0414+009 at 6, 20 and 90 cm show that it has a steep-spectrum (α~1; f_v_ is proportional to v^-α^) radio tail. The tail extends ~40 arcsec from the core, in a gentle curve. There is no evidence of extended emission on the opposite side of the core. This is by far the clearest example of a single-sided…
A search for the 2omega-omega frequency in the X-ray light curves of intermediate polars.
Hellier, Coel
Wynn and King (1992) have shown that diskless accretion gives rise to modulations at either the omega-Omega or 2omega-Omega frequencies in the X-ray light curves of intermediate polars. However, the EXOSAT archive shows no sign of a 2omega-Omega modulation in any of the systems observed. An omega-Omega modulation larger than half the spin-pulse am…
A new kind of oscillation in the persistent emission of the Rapid Burster.
Stella, Luigi; Lewin, Walter H. G.; van Paradijs, Jan +3 more
We present a study of a new kind of oscillation found in the persistent emission after some type II bursts from the Rapid Burster observed during 1985 August with EXOSAT. All 95 bursts observed were longer than 30 s. Ten of them were followed by these oscillations. The frequency of the oscillations ranged from 39 to 56 mHz. A period decrease (by 3…
Pulse phase-resolved X-ray spectroscopy of the transient high-mass X-ray binary V 0332+53.
Coe, M. J.; Unger, S. J.; Lehto, H. J. +1 more
An analysis is conducted of Exosat observations of the transient binary X-ray pulsar V 0332 + 53 during a series of flares, which yielded simultaneous high energy and time resolutions. The results obtained are interpreted in terms of a system in which the line-of-sight from the earth is not close to the magnetic axis of the neutron star, and in wh…
Energy structure of the accretion disc corona in X 1822-371.
Hellier, Coel; Mason, Keith O.; Williams, O. R.
Ginga observations of the LMXB X 1822-371 show that the broad orbital modulation and the eclipse are deeper at higher energies. This is explained if the X-ray emitting corona produces softer emission at greater heights from the disc plane, which suggests that either the corona is optically thick, or that the illuminating X-rays are anisotropic. Fu…