相关论文: A Systematic Study on Energy Dependence of Quasi-P…

We present a study of the centroid frequencies and phase lags of the quasi-periodic oscillations (QPOs) as functions of photon energy for GRS 1915+105. It is found that the centroid frequencies of the 0.5-10 Hz QPOs and their phase lags are…

We report on the timing analysis of RXTE observations of the Galactic micro-quasar GRS 1915+105 performed in 2003. Out of a total of six times ~20 ks, we focus here only on the three observations during which GRS 1915+105 is found in a…

We present a model-independent analysis of the short-timescale energy dependence of low frequency quasi-periodic oscillations (QPOs) in the X-ray flux of GRS 1915+105. The QPO frequency in this source has previously been observed to depend…

We present the results of bicoherence analysis on observations of GRS 1915+105 that exhibit quasi-periodic oscillations (QPOs). The bicoherence is a higher order statistic that can be used to probe the relation between the phases of a…

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 a study of the properties of strong 0.8-3.0 Hz quasi-periodic oscillations (QPOs) that occurred during 1997 RXTE observations of the microquasar GRS 1915+105 in the low-hard state. The high count rates allow us to track…

We analyze a set of three RXTE Target of Opportunity observations of the Galactic microquasar GRS 1915+105, observed on April 2000, during a multi-wavelength campaign. During the three observations, a strong, variable low frequency (2-9 Hz)…

We have used Rossi X-ray Timing Explorer data to measure the lags between soft (2-5 keV) and hard (5-13 keV) photons and to study the aperiodic variability of the superluminal black hole candidate GRS 1915+105 during low-flux states. The…

We show that the galactic microquasar GRS 1915+105 exhibits quasi-periodic oscillations (QPOs) whose frequency varies continuously from 1-15 Hz, during spectrally hard dips when the source is in a flaring state. We report here analyses of…

We report the results of a systematic timing analysis of RXTE observations of GRS 1915+105 when the source was in its variability class theta, characterized by alternating soft and hard states on a time scale of a few hundred seconds. The…

We analyzed two 1996 observations of the Galactic Microquasar GRS 1915+105 taken with the Proportional Counter Array on board the Rossi X-ray Timing Explorer. We focus on the properties of the high-frequency QPO as a function of the `dip'…

From data obtained from the PCA in the 2-11 keV and 11-30.5 keV energy range, GRS 1915+105 is seen during RXTE observations between 1996 May and October on two separate branches in a hardness intensity diagram. On the hard branch, GRS…

In this work, we study the correlation between Quasi-periodic Oscillation (QPO) frequency and the spectral parameters during various X-ray states in the black hole binary GRS 1915+105 which matches well with the predicted relativistic…

Previous analysis of AstroSat observations of the black hole system MAXI J1535-571, have revealed the presence of a strong Quasi-Periodic Oscillation (QPO) whose frequency is correlated with the high energy spectral index. Here, we fit the…

We explore the use of the bispectrum for understanding quasiperiodic oscillations. The bispectrum is a statistic which probes the relations between the relative phases of the Fourier spectrum at different frequencies. The use of the…

We analysed 9 RXTE/PCA observations of GRS 1915+105 in the flaring state, when the hardness of the source spectrum was changing on the time scales from few seconds up to 1000 seconds. The quasi periodic oscillations (QPOs) with the…

I report the discovery of hard X-ray phase lags associated with the famous 67 Hz quasi-periodic oscillation (QPO) in microquasar GRS 1915+105. The QPO is seen on multiple occasions. For this investigation, I have chosen one particular…

The properties of sub-second time variability of the X-ray emission of the black-hole binary GRS 1915+105 are very complex and strictly connected to its patterns of variability observed on long time scales. A key aspect for determining the…

We discover a definite correlation between the frequency of the quasi-periodic oscillations (QPO) in quiescence states and the duration of the quiescence state of the transient X-ray source GRS 1915+105. We find that while the QPO frequency…

We have investigated the Quasi Periodic Oscillation (QPO) properties of the transient accreting X-ray pulsar XTE J1858+034 during the second outburst of this source in April-May 2004. We have used observations made with the Proportional…