Related papers: Rapid Optical Fluctuations in the Black Hole Binar…

The high energy radiation emitted by black hole X-ray binaries originates in an accretion disk, hence the variability of the lightcurves mirrors the dynamics of the disc. We study the time evolution of the emitted flux in order to find…

Diffusivity in some soft matter and biological systems changes with time, called the fluctuating diffusivity. In this work, we propose a novel origin for fluctuating diffusivity based on stochastic simulations of binary gas mixtures. In…

Aims. The optical emission of black hole transients increases by several magnitudes during the X-ray outbursts. Whether the extra light arises from the X-ray heated outer disc, from the inner hot accretion flow, or from the jet is currently…

The simultaneous presence of a strong quasi periodic oscillation of period of about 10 seconds in the optical and X-ray lightcurves of the X-ray transient XTE J1118+480 suggests that a significant fraction of the optical flux originates…

We review X-ray flux modulation from X-ray binaries on time scales corresponding to the orbital period and those at longer time scales (so called superorbital). Those modulations provide a powerful tool to constrain geometry of the…

We analyze the mass distribution of stellar black holes derived from the light and radial velocity curves of optical stars in close binary systems using dynamical methods. The systematic errors inherent in this approach are discussed. These…

Black hole binaries are variable in timescales of rang from months to milli-seconds. The origin of this variability is still not clear, it could be due to the variation of external parameters, like mass accretion rate, instabilities in the…

We review the properties of 40 X-ray binaries that contain either a confirmed black hole or a black hole candidate. After discussing briefly the significance of these Galactic black holes to both astronomy and physics, we present basic data…

The self-lensing of a massive black hole binary (MBHB), which occurs when the two BHs are aligned close to the line of sight, is expected to produce periodic, short-duration flares. Here we study the shapes of self-lensing flares (SLFs) via…

We consider the case of radio flares from black hole X-ray binaries in which the flare spectrum evolves from optically thick to optically thin, under the assumption that this is due to decreasing optical depth to synchrotron self…

We examine the effects of magnetic field on low angular momentum flows with standing shock around black holes in two dimensions. The magnetic field brings change in behavior and location of the shock which results in regularly or…

Accreting black holes are unique tools to understand the physics under extreme gravity. While black hole X-ray binaries differ vastly in mass from AGN, their accretion and ejection flows are assumed to be essentially similar. Black hole…

[Abridged.] We present multiwavelength observations of the black hole binary system, A0620-00. Using the Cosmic Origins Spectrograph on the Hubble Space Telescope, we have obtained the first FUV spectrum of A0620-00. The observed spectrum…

Classically, black Holes have the rigid event horizon. However, quantum mechanically, the event horizon of black holes becomes fuzzy due to quantum fluctuations. We study Hawking radiation of a real scalar field from a fluctuating black…

The tidal disruption event by a supermassive black hole in Swift J1644+57 can trigger limit-cycle oscillations between a supercritically accreting X-ray bright state and a subcritically accreting X-ray dim state. Time evolution of the…

Relativistic outflows are believed to be a common feature of black hole X-ray binaries at the lowest accretion rates, when they are in their `quiescent' spectral state. However, we still lack a detailed understanding of how quiescent jet…

Hard X-ray emission is ubiquitous in accreting black holes, both in Galactic binary systems and in Active Galactic Nuclei. I review the different spectra which can be seen from these systems, and possible ways of producing this emission.…

Blazar OJ287 is a unique source in which optical outbursts with double-peak structure have been observed quasi-periodically with a cycle of 12yr. It may be one of the best candidates for searching supermassive black hole binaries. We…

V616 Mon = A0620-00 is a prototype of black hole transient X-ray binaries. Our 2003-16 optical photometry of the object during X-ray quiescence, obtained by 50-250 cm telescopes in Crimea, Caucasus Mountains and Slovakia, consists of ~ 7660…

Many X-ray binaries remain undetected in the mid-infrared, a regime where emission from their compact jets is likely to dominate. Here, we report the detection of the black hole binary GX 339-4 with the Wide-field Infrared Survey Explorer…