Related papers: A transient low-frequency QPO from the black hole …

High-frequency twin peak quasiperiodic oscillations (QPOs) are observed in four microquasars, i.e., Galactic black hole binary systems, with frequency ratio very close to 3:2. In the microquasar GRS 1915+105, the structure of QPOs exhibits…

The Galactic black hole transient GRS1915+105 is famous for its markedly variable X-ray and radio behaviour, and for being the archetypal galactic source of relativistic jets. It entered an X-ray outburst in 1992 and has been active ever…

The low frequency quasi periodic oscillations (QPOs) are commonly observed during hard states of black hole binaries. Several studies have established various observational/empirical correlations between spectral parameters and QPO…

We present the first detections of the black hole X-ray binary GRS 1915+105 at sub-millimetre wavelengths. We clearly detect the source at 350 GHz on two epochs, with significant variability over the 24 hr between epochs. Quasi-simultaneous…

Based on broadband timing analysis of Insight-HXMT and NICER data from the 2019 outburst of the black hole X-ray binary (BHXRB) MAXI J1348-630, we report the detection of the coexistence and competitive interplay between type-C and type-B…

We compiled the X-ray and soft gamma-ray observations of the Galactic black hole binary XTE J1859+226 in the 1999--2000 outburst from RXTE, ASCA, BeppoSAX and CGRO. Throughout systematic spectral analysis using a two-component model…

While the dynamical origin of the variability observed in Galactic Black hole systems, such as quasi-periodic oscillations (QPOs), are still a matter of debate, insight into the radiative components responsible for such behaviour can be…

We present a systematic spectral-timing analysis of a fast appearance/disappearance of a type-B quasi-periodic oscillation (QPO), observed in four NICER observations of MAXI J1348-630. By comparing the spectra of the period with and without…

We present the results of a detailed analysis of RXTE observations which show an unusual state transition between high-soft and low-soft states in the microquasar GRS 1915+105. The RXTE pointed observations reveal that these events appeared…

Systematically studying all the RXTE/PCA observations for GRS 1915+105 before November 2010, we have discovered three additional patterns in the relation between Quasi-Periodic Oscillation (QPO) frequency and photon energy, extending…

Fast time variability is the most prominent characteristic of accreting systems and the presence of quasi periodic oscillations (QPOs) is a constant in all accreting systems, from cataclysmic variables to AGNs, passing through black hole…

In June 2015, the black hole X-ray binary (BHXRB) V404 Cygni went into outburst for the first time since 1989. Here, we present a comprehensive search for quasi-periodic oscillations (QPOs) of V404 Cygni during its recent outburst,…

In the context of black hole spin in X-ray binaries, we propose that certain type of quasi-period oscillations (QPOs) observed in the light curves of black hole binaries (BHBs) are produced by X-ray modulation at the precession frequency of…

We report the discovery of two new types of variability in the neutron star low-mass X-ray binary MXB 1730-335 (the 'Rapid Burster'). In one observation in 1999, it exhibits a large-amplitude quasi-periodic oscillation with a period of…

Most models of the low frequency quasi periodic oscillations (QPOs) in low-mass X-ray binaries (LMXBs) explain the dynamical properties of those QPOs. On the other hand, in recent years reverberation models that assume a lamp-post geometry…

The evolution of different types of quasi-periodic oscillations (QPOs) and the coupled radiative/physical changes in the accretion disk are still poorly understood. In a few black hole binaries it was found that fast evolution of QPOs is…

Quasi-periodic oscillation (QPO) detected in the X-ray radiation of black hole X-ray binaries (BHXBs) is thought to originate from dynamical processes in the close vicinity of the black holes (BHs), and thus carries important physical…

The luminous X-ray binary and black-hole candidate LMC X-1 has been observed with the Rossi X-ray Timing Explorer (RXTE) to search for quasi-periodic oscillations (QPO), previously reported in its high state. The source was observed monthly…

We analysed the Rossi X-ray Timing Explorer (RXTE) data from a sample of bright accreting neutron star (NS) low-mass X-ray binaries (LMXBs). With the aim of studying the quasi-periodic variability as a function of the accretion regime, we…

We have compared simultaneous Ryle Telescope radio and Rossi X-Ray Timing Explorer X-ray observations of the galactic microquasar GRS 1915+105, using the classification of the X-ray behaviour in terms of three states as previously…