The well-known black-hole X-ray transient A0620−00 was a bright radio source during the first part of its outburst in 1975. We have revisited the available data and find for the first time evidence that the source exhibited multiple jet ejections. Rapid radio spectral changes indicate the addition of at least three new components which are initially optically thick. From single baseline interfe...

Context. Dwarf nova outbursts result from enhanced mass transport through the accretion disc of a cataclysmic variable system. Aims. We assess the question of whether these outbursts are caused by an enhanced mass transfer from the late-type main sequence star onto the white dwarf (so-called mass transfer instability model, MTI) or by a thermal instability in the accretion disc (disc instabilit...

We reanalyse archival GINGA and ASCA X–ray data from SS Cyg in both quiescence and outburst, using multi–temperature plasma models for the continuum and line emission, together with their reflection from the X–ray illuminated white dwarf and accretion disk. Reflection is clearly detected in all the spectra, but its contribution is larger in the softer X–ray spectra seen in outburst than in quie...

Tectonic coal seams are characterized by soft, low permeability and high gas outburst. The traditional control method is the intensive drilling extraction in this seam, which not only large engineering quantity, cost, difficult to form holes efficiency, but also easy induce outburst, a problem for global mine control. To solve problem, controllable shockwave equipment developed author’s team su...

Time resolved spectroscopic observations of U Gem during its March 2000 outburst show strong spiral shocks in the accretion disk. During the plateau at maximum brightness the spiral shocks contribute ∼14% to the total He II flux. The two arms of the spiral show a distinctly different evolution during the outburst and decline, which indicates an asymmetric evolution in the disk.

The black hole candidate XTE J1817-330 was discovered in outburst on 26 January 2006 with RXTE/ASM. One year later, on 28 February 2007, another X-ray transient discovered in 1996, XTE J1856+053, was detected by RXTE during a new outburst. We report on the spectra obtained by XMM-Newton of these two black hole candidates.