Rashid A. Sunyaev

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We report the results of identification of 8 hard X-ray sources discovered by the INTEGRAL observatory during the ongoing all-sky survey. These sources have been observed by Chandra. In 6 cases a bright X-ray source was found within the INTEGRAL localization region, which enabled us to unambigously identify 5 of the objects with nearby galaxies, implying(More)
Observations of the diffuse emission in the 8–22 keV energy range, elongated parallel to the Galactic plane (Sunyaev et al. 1993) and detection of the strong 6.4 keV fluorescent line with ∼ 1 keV equivalent width from some giant molecular clouds (e.g. Sgr B2) in the Galactic Centre region (Koyama 1994) suggest that the neutral matter of these clouds is (or(More)
We derive the non-linear relation between the core flux Fν of accretion powered jets at a given frequency and the mass M of the central compact object. For scale invariant jet models, the mathematical structure of the equations describing the synchrotron emission from jets enables us to cancel out the model dependent complications of jet dynamics, retaining(More)
The metallicity evolution and ionization history of the universe must leave its imprint on the Cosmic Microwave Background through resonant scattering of CMB photons by atoms, ions and molecules. These transitions partially erase original temperature anisotropies of the CMB, and also generate new fluctuations. In this paper we propose a method to determine(More)
Solar flare observations in the deka-keV range are performed by the WATCH experiment on board the GRANAT satellite. The WATCH experiment is presented, including the energy calibration as applied in the present work. The creation of the solar burst catalogue covering two years of observation is described and some examples of solar observations are given. The(More)
Aims. We study the hard X-ray luminosity function and absorption distribution of local (z ∼< 0.1) active galactic nuclei (AGN) and discuss the implications for AGN cosmological evolution and for the cosmic X-ray background (CXB). Methods. We use the INTEGRAL all-sky hard X-ray survey to perform a statistical study of a representative sample of nearby AGN.(More)
The boundary layer where the accretion disk meets the star is expected to be the dominant source of high-energy radiation in low-mass X-ray binaries which contain weakly magnetized accreting neutron stars. We present solutions for the structure of the boundary layer in such a system. We find that the main portion of the boundary layer gas is hot (∼> 10 K),(More)
Information about the X-ray luminosity of the supermassive black hole located at the Galactic center (GC), Sgr A, and its temporal variations in the past is imprinted in the scattered emission observed today in the direction towards giant molecular clouds (GMCs) located in our Galaxy. Due to light travel time effects these clouds probe the activity of Sgr A(More)