Related papers: Stronger Reflection from Black Hole Accretion Disk…

The X-ray spectra of accreting stellar-mass black hole systems exhibit spectral features due to reflection, especially broad iron K alpha emission lines. We investigate the reflection by the accretion disc that can be expected in the…

Continuum and reflection spectral models have each been widely employed in measuring the spins of accreting black holes. However, the two approaches have not been implemented together in a photon-conserving, self-consistent framework. We…

Understanding the dynamics behind black hole state transitions and the changes they reflect in outbursts has become long-standing problem. The X-ray reflection spectrum describes the interaction between the hard X-ray source (the power-law…

We analyze {\it simultaneously} six composite {\it RXTE} spectra of GX 339--4 in the hard state comprising 77 million counts collected over 196 ks. The source spectra are ordered by luminosity and spanthe range 1.6\% to 17\% of the…

Most black hole candidates exhibit characteristic power-law like hard X-ray emission above $\sim$ 10 keV. In the {\em high state}, in which 2 -- 10 keV luminosity is relatively high, the energy index of the hard X-ray emission is usually…

We study reflected X-ray emission that returns to the accretion disc in the strong gravitational fields around black holes using General Relativistic ray tracing and radiative transfer calculations. Reflected X-rays that are produced when…

Accreting black holes show a complex and diverse behaviour in their soft spectral states. Although these spectra are dominated by a soft, thermal component which almost certainly arises from an accretion disc, there is also a hard X-ray…

We present a series of monitoring observations of the ultrasoft broad-line AGN RE J2248-511 with XMM-Newton. Previous X-ray observations showed a transition from a very soft state to a harder state five years later. We find that the…

Selected topics dealing with X-ray/soft gamma-ray emission from accreting black-hole sources are reviewed. The shape of soft gamma-ray spectra of Seyferts observed by OSSE can be well modelled by thermal Comptonization. A very strong…

We present the results of a new global radiation transport code coupled to a general relativistic magneto-hydrodynamic simulation of an accreting, non-rotating black hole. For the first time, we are able to explain from first principles in…

We review observations and theoretical models of X-ray/gamma-ray spectra of radio-quiet Seyfert galaxies and of Galactic black-hole candidates (in the hard spectral state). The observed spectra share all their basic components: an…

The models that seek to explain the reflection spectrum in black hole binaries usually invoke a point-like primary source of hard X-rays. This source illuminates the accretion disk and gives rise to the discrete (lines) and…

Most of the luminosity of accreting black hole is emitted in the X-ray band. This radiation is believed to emerge, through inverse Compton process, from a hot (Te ~ 10^8 -10^9 K) optically thin (Thomson optical depth ~ 1) plasma probably…

We present a survey of how the spectral features of black hole X-ray binary systems depend on spin, accretion rate, viewing angle, and Fe abundance when predicted on the basis of first principles physical calculations. The power law…

Any cold, optically-thick matter in the vicinity of an accreting black hole, such as the accretion disk, can intercept and reprocess some fraction of the hard X-ray continuum emission, thereby imprinting atomic features into the observed…

We present a detailed spectral analysis of the Black Hole Binary XTE J1752-223 in the hard state of its 2009 outburst. Regular monitoring of this source by RXTE provided high signal-to-noise spectra along the outburst rise and decay. During…

The degree to which the thin accretion disks of black hole X-ray binaries are truncated during hard spectral states remains a contentious open question in black hole astrophysics. During its singular observed outburst in…

We present a high density disc reflection spectral analysis of a sample of 17 Seyfert 1 galaxies to study the inner disc densities at different black hole mass scales and accretion rates. All the available XMM-Newton observations in the…

We present X-ray/gamma-ray observations of Cyg X-1 in the soft state during 1996 May-June. We analyze ASCA, RXTE and OSSE data. The spectrum consists of soft X-ray blackbody emission of an optically thick accretion disk in the vicinity of a…

Relativistic reflection features in the X-ray spectra of black hole binaries and AGNs are thought to be produced through illumination of a cold accretion disk by a hot corona. In this work, we assume that the corona has the shape of an…