Related papers: Probing the temporal variability of Cygnus X-1 int…
We present the analysis of two long, quasi-uninterrupted RXTE observations of Cygnus X-1 that span several days within a 10 d interval. The spectral characteristics during this observation cover the region where previous observations have…
The Neutron Star Interior Composition Explorer (NICER) monitoring campaign of Cyg X-1 allows us to study its spectral-timing behavior at energies ${<}1$ keV across all states. The hard state power spectrum can be decomposed into two main…
Application of multi-resolution analysis adopting wavelets in order to investigate millisecond aperiodic X-ray variability of Cyg X-1 is presented. This relatively new approach in a time-series analysis allows us to study both the…
Analyzing the archival data from the Rossi X-ray Timing Explorer (RXTE), we study the power density spectra (PDS) of Cygnus X-1 from 1996 to 2003 in the frequency range of 0.01 - 25 Hz. With our model we are able to track the evolution of…
We present the long term evolution of the timing properties of the black hole candidate Cygnus X-1 in the 0.002-128 Hz frequency range as monitored from 1998 to 2001 with the RXTE. The hard state power spectral density (PSD) is well modeled…
We present temporal and spectral results from monitoring Cygnus X-1 with the Rossi X-ray Timing Explorer (RXTE) in 1998 and 1999. We concentrate on the long term evolution of the hard state timing properties, comparing it to the 1996 soft…
We report the results from our timing analysis of 15 RXTE observations of Cygnus X-1 throughout its 1996 spectral transitions. The entire period can be divided into 3 distinct phases: (1) transition from the hard to soft state, (2) soft…
We present the results from the RXTE observations of Cygnus X-1 in its high state. In the energy range of 2-200 keV, the observed X-ray spectrum can be described by a model consisting of a soft blackbody component and a broken power-law…
We study the soft X-ray variability of Cygnus X-3. By combining data from the All-Sky Monitor and Proportional Counter Array instruments on the RXTE satellite with EXOSAT Medium Energy (ME) detector observations, we are able to analyse the…
We present the most extensive analysis of Fourier-based X-ray timing properties of the black hole binary Cygnus X-1 to date, based on 12 years of bi-weekly monitoring with RXTE from 1999 to 2011. Our aim is a comprehensive study of timing…
We reported previously that for Cyg X-1 there is a settling period following the transition from hard to soft state (astro-ph/9610071). During the transiton, The low energy spectrum (below ~10 keV) varies significantly from observation to…
We report the first analysis of data from AstroSat/LAXPC observations of Cygnus X-1 in January 2016. LAXPC spectra reveals that the source was in the canonical hard state, represented by a prominent thermal Comptonization component having a…
(abbreviated abstract) We present the long term spectral evolution of the Galactic black hole candidate Cygnus X-1 in the X-rays and at 15GHz using ~200 pointed observations taken between early 1999 and late 2004 with RXTE and the Ryle…
We study a large sample of RXTE PCA/HEXTE observations of Cyg X-1. We characterize the spectra by soft and hard X-ray colours (which define the spectral states), and fit them with a physical model of hybrid, thermal/non-thermal…
For the very first time, we report the high frequency analysis of Cyg X-1 up to hard X-ray using SPI on-board INTEGRAL. After analyzing the possible contribution fromthe background, and using INTEGRAL archive from March 2005 to May 2008,…
We present an analysis of all observations of Cygnus X-1 by the BATSE (20-300 keV) and by ASM (1.5-12 keV) until 2002 June, including 1200 days of simultaneous data. We find a number of correlations between fluxes and hardnesses in…
We report continuous monitoring of Cygnus X-1 in the 1.3 to 200 keV band using ASM/RXTE and BATSE/CGRO for about 200 days from 1996 February 21 to 1996 early September. During this period Cygnus X-1 experienced a hard-to-soft and then a…
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…
The study of fast variability properties in X-ray binaries advances our understanding of the physical processes and geometric properties of the accretion flow around the compact object. In this work, we study the evolution of the timing…
We report the results of an observation of Cygnus X-1 with INTEGRAL, that we combine with simultaneous radio observations with the Ryle telescope. Both spectral and variability properties of the source indicate that Cygnus X-1 was in an…