Related papers: Exotic optical variability in the black hole X-ray…
We present results from modeling of quasi-simultaneous broad band (radio through X-ray) observations of the galactic stellar black hole (BH) transient X-ray binary (XRB) systems XTE J1118+480 and GX 339-4 using an irradiated disc + compact…
We present the results of long-term monitoring of the X-ray emission from the ultraluminous X-ray source XMMUJ122939.9+075333 in the extragalactic globular cluster RZ2109. The combination of the high X-ray luminosity, short term X-ray…
We report on a Chandra grating observation of the recently discovered hard X-ray transient IGR J17497-2821. The observation took place about two weeks after the source discovery at a flux level of about 20 mCrab in the 0.8-8 keV range. We…
One of the most recent discoveries of the INTEGRAL observatory is the existence of a previously unknown population of X-ray sources in the inner arms of the Galaxy. IGR J17544-2619, IGR J16465-4507 and XTE J1739-302 are among these sources.…
The hard X-ray source IGR J11215-5952 is a peculiar transient, displaying very short X-ray outbursts every 165 days. We obtained high-resolution spectra of the optical counterpart, HD 306414, at different epochs, spanning a total of three…
Weakly accreting black hole X-ray binaries launch compact radio jets that persist even in the quiescent spectral state, at X-ray luminosities <1e-5 of the Eddington luminosity. However, radio continuum emission has been detected from only a…
The origins of X-ray and radio emissions during an X-ray binary outburst are comparatively better understood than those of ultraviolet, optical and infrared radiation. This is because multiple competing mechanisms peak in these mid-energy…
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…
Isolated black holes and neutron stars can be revealed through the observation of long duration gravitational microlensing events. A few candidates have been found in surveys of stars in the direction of the Galactic bulge. Recently, thanks…
Here we study the rapid X-ray variability (using XMM-Newton observations) of three neutron-star low-mass X-ray binaries (1RXS J180408.9-342058, EXO 1745-248, and IGR J18245-2452) during their recently proposed very hard spectral state…
BD+6073 is the optical counterpart of the X-ray source IGR J00370+6122, a probable accretion-powered X-ray pulsar. The X-ray light curve of this binary system shows clear periodicity at 15.7 d, which has been interpreted as repeated…
We present results of analysis of observations of two transient sources IGR J17091-3624 and IGR J18539+0727 in April 2003 with RXTE observatory. Obtained energy spectra of sources, and also power spectra of their flux variations give us a…
We investigate properties of iron fluorescent line arising as a result of illumination of a black hole accretion disc by an X-ray source located above the disc surface. We study in details the light-bending model of variability of the line,…
We combine infrared spectra in the I, J, H and K bands together with JHK photometry to characterize the spectral type, luminosity class and distance to the infrared counterparts to five INTEGRAL sources. For SAX J18186-1703 and IGR…
We report the first time-series of broadband infrared (IR) color measurements of Sgr A*, the variable emission source associated with the supermassive black hole at the Galactic Center. Using the laser and natural guide star AO systems on…
AX J0049.4-7323 is a Be/X-ray binary in the Small Magellanic Cloud hosting a ~750 s pulsar which has been observed over the last ~17 years by several X-ray telescopes. Despite numerous observations, little is known about its X-ray…
We use both time-domain and Fourier techniques to study the correlated optical and X-rays variability in the black hole X-ray nova XTE J1118+480. Its X-ray timing properties, such as the shape of the X-ray power spectrum and…
We present six years of optical monitoring of the black hole candidate X-ray binary Swift J1357.2-0933, during and since its discovery outburst in 2011. On these long timescales, the quiescent light curve is dominated by high amplitude,…
We report on the results of X-ray observations of 4XMM J111816.0-324910, a transient ultra-luminous X-ray source located in the galaxy NGC 3621. This system is characterised by a transient nature and marked variability with characteristic…
IGR J11305-6256 is one of the numerous sources discovered through the INTEGRAL scan of the Galactic Plane. Thanks to the Swift-BAT survey, that allows the frequent sampling of any sky region, we have discovered in the hard X-ray emission of…