Related papers: The rms-flux relations in different branches in Cy…
We study the long term evolution of the relationship between the root mean square (rms) variability and flux (the ``rms-flux relation'') for the black hole Cygnus X-1 as monitored from 1996 to 2003 with the Rossi X-ray Timing Explorer…
The rms (root mean square) variability is the parameter for understanding the emission temporal properties of X-ray binaries (XRBs) and active galactic nuclei (AGN). The rms-flux relation with Rossi X-ray Timing Explorer (RXTE) data for the…
A linear dependence of the amplitude of broadband noise variability on flux for GBHC and AGN has been recently shown by Uttley & McHardy (2001). We present the long term evolution of this rms-flux-relation for Cyg X-1 as monitored from…
We report the first detection of a linear correlation between rms variability amplitude and flux in the Ultraluminous X-ray source NGC 5408 X-1. The rms-flux relation has previously been observed in several Galactic black hole X-ray…
A linear relation between absolute rms variability and flux in X-ray observations of compact accreting sources has recently been identified. Such a relation suggests that X-ray lightcurves are non-linear and composed of a lognormal…
We observed the low mass X-ray binary Cyg X-2 for a total of 18 nights over two observing runs in July and September of 2006, using the Otto Struve Telescope at McDonald Observatory and the Rossi X-ray Timing Explorer. Using discrete cross…
We have investigated the short term linear relation between the rms variability and the flux in 1,961 observations of 9 black hole X-ray binaries. The rms-flux relation for the 1-10 Hz range is ubiquitously observed in any observation with…
Recent analysis of blazar variability has revealed a proportionality between the mean flux and the root mean squared (rms) fluctuations about the mean flux. Although such rms-flux relation has been previously observed in the accretion…
We present an analysis of the short timescale variations in the properties of the strong (type "C") quasi-periodic oscillation observed in XTE J1550-564 during its 1998 outburst. In particular, the QPO shows a correlation between absolute…
We present results of RXTE observations of the X-ray source Cyg X-2 during 1996-1999. Its power density spectra in the 0.1-128-Hz band are fitted by a model that takes into account the power-law spectral behavior at frequencies below and…
We present the rms-intensity diagram for black hole transients. Using observations taken with the Rossi X-ray timing explorer we study the relation between the root mean square (rms) amplitude of the variability and the net count-rate…
We report the discovery of a linear relationship between the root-mean-square (rms) variability amplitude and the mean flux in the accreting white dwarf binary system MV Lyrae. Our lightcurve, obtained with the Kepler satellite, spans 633…
We review the longterm confusion which has existed over the nature of flaring in the brightest class of low mass X-ray binary: the Z-track sources, specifically in the Cygnus X-2 sub-group. Intensity reductions in the lightcurve produce a…
The aperiodic X-ray variability in neutron star and black hole X-ray binaries (XRBs), and active galactic nuclei (AGN) shows a characteristic linear relationship between rms amplitude and flux, implying a multiplying-together or `coupling'…
We show that the rms-flux relation recently discovered in the X-ray light curves of Active Galactic Nuclei (AGN) and X-ray binaries (XRBs) implies that the light curves have a formally non-linear, exponential form, provided the rms-flux…
It is known that the overall (mean) intensity of the low-mass X-ray binary Cyg X-2 varies on time scales from a day to months, independently from the variations on time scales of hours to a day by which the source moves between the…
We report the detections of the anti-correlated soft and hard X-rays, and the time lags of $\sim$ hecto-second from the neutron star low-mass X-ray binary Cyg X-2, a well-known Z-type luminous source. Both the anti-correlation and the…
We investigated the time lags and the evolution of the cross spectra of Z source GX~5-1, observed by the Rossi X-ray Timing Explorer (RXTE), when it is in the horizontal branch oscillations. We showed that the time lags of 3 horizontal…
We analyze simultaneous radio-X-ray data of Cygnus X-1 from the Ryle telescope (RT) and RXTE over more than 4 a. We show that apparent correlations on short time scales in the lightcurves of Cyg X-1 are probably the coincidental outcome of…
The X-ray variability of active galactic nuclei (AGN) carries crucial information about the X-ray radiation mechanism. We performed a systematic study of the X-ray short-term (1-100 ks timescale) variability for a large sample of 78…