Related papers: Is the `IR Coincidence' Just That?
The high-frequency bump, characterized by a frequency exceeding ~30 Hz, represents a seldom-explored time-variability feature in the power density spectrum (PDS) of black-hole X-ray binaries. In the 2002, 2004, 2007 and 2010 outbursts of GX…
Analysis was made of the multiple XTE/PCA data on the promised black hole candidate with superluminal jet, GRO J1655-40, acquired during its 1996--1997 outburst. The X-ray spectra can be adequately described by the sum of an optically thick…
HETE-2 has provided strong evidence that the properties of X-Ray Flashes (XRFs) and GRBs form a continuum, and therefore that these two types of bursts are the same phenomenon. We show that both the structured jet and the uniform jet models…
We summarize recent observations of Cyg X-1 during its 1996 state transition. The results favor an emission geometry with a central optically thin corona surrounded by an optically thick, geometrically thin accretion disk. As the soft state…
In order to test the recently proposed classification of the radio/X-ray states of the X-ray binary Cyg X-3, we present an analysis of the radio data available for the system at much higher spatial resolutions than used for defining the…
We present a spectro-timing analysis of the black hole X-ray transient GX 339-4 using simultaneous observations from Astrosat and NICER during the 2021 outburst period. The combined spectrum obtained from NICER, LAXPC, and SXT data is…
We report BeppoSAX and optical observations of the black hole candidate GX 339-4 during its X-ray `off' state in 1999. The broad-band (0.8-50 keV) X-ray emission can be fitted by a single power law with spectral index, \alpha ~1.6. The…
Recently a correlation between the radio and X-ray luminosities is found, $L_{\rm R}\propto L_{\rm X}^{0.7}$, in black hole sources including black hole candidates in our galaxy and active galactic nuclei. We first show that the correlation…
We performed a time-resolved spectral analysis of 53 bright gamma-ray bursts (GRBs) observed by \textit{Fermi}/GBM. Our sample consists of 908 individual spectra extracted from the finest time slices in each GRB. We fitted them with the…
We examine a systematic comparison of jet-knots, hotspots and radio lobes recently observed with Chandra and ASCA. This report will discuss the origin of their X-ray emissions and investigate the dynamics of the jets. The data was compiled…
Aims: The nature of Cygnus X-3 is still not understood well. This binary system might host a black hole or a neutron star. Recent observations by INTEGRAL have shown that Cygnus X-3 was again in an extremely ultrasoft state. Here we present…
A characteristic feature of the Fourier Power Density Spectrum (PDS) observed from black hole X-ray binaries in low/hard and intermediate spectral states is a broad band-limited noise, characterized by a constant below some frequency (a…
We present an analysis of the relativistic reflection spectra of GX 339-4 during the hard-to-soft transition of its 2021 outburst observed by Insight-HXMT. The strong relativistic reflection signatures in the data suggest a high black hole…
Multi-wavelength observations of Galactic black hole candidate sources indicate a close connection between the accretion disk emission and the jet emission. The recent discovery of an anti-correlated time lag between the soft and hard…
The black hole X-ray transient GX 339$-$4 was observed with the {\it Swift} satellite across the hard-to-soft state transition during its 2010 outburst. The ultraviolet (UV) flux measured with the filter UVW2 of the {\it Swift}/UVOT started…
The radiative process responsible for gamma-Ray Burst (GRB) prompt emission has not been identified yet. If dominated by fast-cooling synchrotron radiation, the part of the spectrum immediately below the $\nu F_\nu$ peak energy should…
Starting from the assumption that radio jets and accretion disks are symbiotic features present in radio loud and radio quiet quasars we scale the bulk power of radio jets with the accretion power by adding mass- and energy conservation of…
We report results from simultaneous ASCA and RXTE observations of Cyg X-1 when the source made a rare transition from the hard (= low) state to the soft (= high) state in 1996. These observations together cover a broad energy range ~0.7--50…
We analyse five observations of the X-ray binary GX 339-4 by the soft gamma-ray OSSE detector on board CGRO simultaneous with either Ginga or RXTE observations. The source was bright during four of them, with the luminosity of L ~ 10^{37}…
The nearby accreting neutron star binary Sco X-1 is the closest example of ongoing relativistic jet production at high Eddington ratios. Previous radio studies have revealed that alongside mildly relativistic, radio-emitting ejecta, there…