Piotr T. Życki

TL;DR: In this paper, the authors reanalyse archival Ginga data of the soft X-ray transient source GS 20231338 covering the beginning of its 1989 May outburst, showing that the source showed a number of rather unusual features: very high and apparently saturated luminosity, dramatic flux and spectral variability (often on,1 s time-scale), with no obvious soft thermal component characteristic for soft/high state.

TL;DR: In this article, the broadband X-ray spectrum of Cyg X-1 in the low/hard state as observed by the instruments on board BeppoSAX was presented.

TL;DR: In this article, the authors show that the observable Kerr disk spectra become significantly harder than Schwarzschild disk spectras only when the disk is highly inclined, and they suggest that the slim disk (advection-dominated optically thick disk) model is likely to explain the observed super-Eddington luminosities, hard energy spectra, and spectral variations of ULXs.

TL;DR: In this paper, the relativistically smeared Compton-re ected continuum and iron fluorescent line near 6.5 keV produced by X-ray illumination of the accretion disc were analyzed.

TL;DR: In this paper, the vertical structure of a radiation-pressure-dominated disc with a hot corona was studied, and the presence of the corona modifies considerably the density and the opacity of the disc surface layers, which are important from the point of view of spectrum formation.