Related papers: Long time-scale variability in GRS1915+105
We present new insights about accretion and ejection physics based on joint RXTE/Chandra HETGS studies of rapid X-ray variability in GRS 1915+105. For the first time, with fast phase-resolved spectroscopy of the rho state, we are able to…
We have analyzed the spectral variations of the superluminal black-hole X-ray binary GRS 1915+105 by using data obtained with the PCA on the Rossi XTE. We find that, despite the marked differences in the structure and the time scale of…
The RXTE observations of GRS 1915+105 have given a new impulse to the study of spectral and timing properties of the X-ray emission of black hole candidates. At variance with any other known source, GRS 1915+105 shows dramatic changes on…
Long-term observations have shown that black hole X-ray binaries exhibit strong, aperiodic variability on time-scales of a few milliseconds to seconds. The observed light curves display various characteristic features like a log-normal…
GRS 1915+105 is a transient black hole X-ray binary consistently emitting 10-100% of the Eddington luminosity in the X-ray band during the last three decades until mid-2018 when the source luminosity suddenly decreased by an order of…
Using high-resolution general relativistic magnetohydrodynamic (GRMHD) simulations, we investigate accretion flows around spinning black holes and identify three distinct accretion states. Our results suggest the origin of the complex…
Using non-linear time series analysis, along with surrogate data analysis, it is shown that the various types of long term variability exhibited by the black hole system GRS 1915+105, can be explained in terms of a deterministic non-linear…
We use data obtained with the PCA onboard RXTE to analyze the spectral variations of the black hole candidate and superluminal source GRS 1915+105. Our results suggest that despite the complicated structure of the X-ray light curve, all…
The UV emission from X-ray binaries, is more likely to be produced by reprocessing of X-rays by the outer regions of an accretion disk. The structure of the outer disk may be altered due to the presence of X-ray irradiation and we discuss…
Black hole binary transients undergo dramatic evolution in their X-ray timing and spectral behaviour during outbursts. In recent years a paradigm has arisen in which "soft" X-ray states are associated with an inner disc radius at, or very…
GRS 1915+105, one of the two known galactic microquasars, shows an extremely complex variability in the X-ray band, comparable to no other X-ray source in the sky. Making use of RXTE/PCA data, we have analyzed the X-ray spectral…
We present X-ray observations of the Black-Hole Binary GRS 1915+105 made with the RXTE (Rossi X-ray Timing Explorer). We concentrated on timing analysis of the strong variability focusing on its aperiodic variability on short (<1s) time…
Currently available information on fast variability of the X-ray emission from accreting collapsed objects constitutes a complex phenomenology which is difficult to interpret. We review the current observational standpoint for black-hole…
We model non-thermal emission spectrum of the extremely sub-Eddington X-ray binary system A0620-00. It is believed that this non-thermal emission is produced by a radiatively inefficient "quiescent" accretion onto a stellar-mass black hole…
Rapid, large amplitude variability at optical to X-ray wavelengths is now seen in an increasing number of Seyfert galaxies and luminous quasars. The variations imply a global change in accretion power, but are too rapid to be communicated…
We perform a three-dimensional general relativistic radiation magnetohydrodynamics simulation of a tilted super-Eddington accretion disk around the spinning black hole (BH). The disk, that tilts and twists as it approaches the BH, precesses…
Black hole binaries exhibit dramatic changes in their X-ray spectral and timing properties over time, providing important clues about the physical processes that occur in these systems. Black holes and black hole candidates are prime…
Multiwavelength variability data, combined with spectral-timing analysis techniques, provides information about the causal relationship between different physical components in accreting black holes. Using fast-timing data and long-term…
The high state of black hole candidates is characterized by a quasi- thermal emission component at $kT \sim 1$ keV. In addition, this state tends to have very low variability which indicates that it is relatively stable, at least on {\it…
Black hole binary systems can emit very bright and rapidly varying X-ray signals when material from the companion accretes onto the black hole, liberating huge amounts of gravitational potential energy. Central to this process of accretion…