相关论文: X/gamma-ray emission from hot accretion flows in A…

Black hole (BH) mergers are natural sources of gravitational waves (GWs) and are possibly associated with electromagnetic events. Such events from a charged rotating BH with an accretion on to it could be more energetic and…

We present models of the soft X-ray transients, A0620-00, V404 Cyg, and X-ray Nova Mus 1991, in quiescence. In each source, we postulate that there is an outer region, extending outward from about 3000 Schwarzschild radii, where the…

Recent hydrodynamical simulations of radiatively inefficient black hole accretion flows with low viscosity have demonstrated that these flows differ significantly from those described by an advection-dominated model. The black hole flows…

General properties of advection-dominated accretion flows are discussed. Special emphasis is given to the optically thin branch of solutions, which has very high ion and electron temperatures and is thermally stable. This solution branch…

Accreting black holes are believed to emit X-rays which then mediate information about strong gravity in the vicinity of the emission region. We report on a set of new routines for the Xspec package for analysing X-ray spectra of black-hole…

We report results obtained from six XMM-Newton observations of the Seyfert galaxy 1H 0419-577. Here we show that the X-ray spectrum and variability are well described by a two-component model comprising a power law with constant spectral…

Aims: Probe the high-energy ($>$60 MeV) emission from the black hole X-ray binary system, Cygnus X-1, and investigate its origin. Methods: We analysed 7.5 yr of data by Fermi/LAT with the latest PASS8 software version. Results: We report…

The recent detection of a three-hour X-ray flare from Sgr A* by Chandra provides very strong evidence for a compact emitting region near this supermassive black hole at the Galactic center. Sgr A*'s mm/sub-mm spectrum and polarimetric…

We present the first fully relativistic prediction of the electromagnetic emission from the surrounding gas of a supermassive binary black hole system approaching merger. Using a ray-tracing code to post-process data from a general…

This paper surveys our current knowledge of the hard X-ray emission properties of old accreting neutron stars in low mass X-ray binaries. Hard X-ray components extending up to energies of a few hundred keV have been clearly detected in…

The X-ray, Ultraviolet, Optical emission from radio-quiet AGNs, black hole binaries, and other compact sources, in general, follow a lognormal flux distribution, a linear rms-flux relation, and a (broken) power-law power spectral densities…

We study the formation of the spectra in advection dominated accretion flows (ADAFs) around Kerr black holes. We use a Monte Carlo approach and fully general relativistic treatment to follow the paths of individual photons and model their…

We performed detailed calculations of the relativistic effects acting on both the reflection continuum and the iron line from accretion discs around rotating black holes. Fully relativistic transfer of both illuminating and reprocessed…

The phenomenology of accretion disc, coronnae and jets in X-ray binaries is rather well established. However the structure of the accretion flow in the various spectral states is still debated and the connection between the hot flow and…

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 study the hard-X-ray spectral properties of ten highly luminous radio-quiet (RQ) active galactic nuclei (AGNs) at z=1.3-3.2, including new XMM-Newton observations of four of these sources. We find a significant correlation between the…

The origin of outflow in narrow-line region (NLR) of active galactic nucleus (AGN) is studied in this paper by focusing on the relationship between the [\ion{O}{3}]$\lambda$5007 line profile and the hard X-ray (in a bandpass of 2-10 keV)…

In a draining rotating fluid flow background, surface perturbations behave as a scalar field on a rotating effective black hole spacetime. We propose a new model for the background flow which takes into account the varying depth of the…

The correlation between radio and X-ray luminosity in the hard state of black hole X-ray binaries is important for unveiling the relation between the accretion flow and the jets. In this paper, we have modeled the quasi-simultaneous…

The X-ray and radio flares observed in X-ray binaries and active galactic nuclei (AGN) are attributed to energetic electrons in the plasma ejecta from the accretion flows near the black hole in these systems. It is argued that magnetic…