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Modelling the behaviour of accretion flows in X-ray binaries
We review how the recent increase in X-ray and radio data from black hole and neutron star binaries can be merged together with theoretical advances to give a coherent picture of the physics of the
Is the soft excess in active galactic nuclei real
We systematically analyse all publicly available XMM–Newton spectra of radio-quiet PG quasars. The soft X-ray excess in these objects is well modelled by an additional, cool, Compton scattering
The ultraluminous state
We revisit the question of the nature of ultraluminous X-ray sources (ULXs) through a detailed investigation of their spectral shape, using the h ighest quality X-ray data available in the XMM-Newton
Intrinsic disc emission and the soft X‐ray excess in active galactic nuclei
Narrow-line Seyfert 1 (NLS1) galaxies have low-mass black holes and mass accretion rates close to (or exceeding) Eddington, so a standard blackbody accretion disc should peak in the extreme
A periodicity of ∼1 hour in X-ray emission from the active galaxy RE J1034+396
The discovery of an ∼1-hour X-ray periodicity in a bright active galaxy, RE J1034+396, which is highly statistically significant and very coherent, with quality factor Q > 16.
Simultaneous X-ray and 7-ray observations of Cyg X-1 in the hard state by Ginga and OSSE
We present four X-ray/gamma-ray spectra of Cyg X-1 observed in the hard ('low') state simultaneously by Ginga and GRO/OSSE on 1991 July 6. The 3-30 keV Ginga spectra are well represented by power
Black hole accretion discs: reality confronts theory
Disc spectra from highly luminous black hole binaries are observed to be rather simple, despite theoretical predictions to the contrary. We collate the disc-dominated spectra from multiple
We report on Rossi X-Ray Timing Explorer observations of four type I X-ray bursters, namely, 1E 1724-3045, GS 1826-238, SLX 1735-269, and KS 1731-260. The first three were in a low state, with 1-200
The 1989 May outburst of the soft X‐ray transient GS 2023+338 (V404 Cyg)
We reanalyse archival Ginga data of the soft X-ray transient source GS 20231338 covering the beginning of its 1989 May outburst. The source showed a number of rather unusual features: very high and
An ionized accretion disk in Cygnus X-1
Results of an analysis of archival Exosat and HEAO 1-A2 observations of Cyg X-1 are presented. It is found, in agreement with Ebisawa (1991), that the X-ray spectrum of Cyg X-1 exhibits a