Related papers: Multiple X-ray reflection from ionized slabs
In most accreting black-hole systems the copious X-rays commonly observed from the inner-most regions are accompanied by a reflection spectrum. The latter is the signature of energetic photons reprocessed by the optically thick material of…
Active Galactic Nuclei (AGN) are the most luminous persistent objects in the universe. An excess of X-ray emission below about 2 keV, called soft-excess, is very common in Type 1 AGN spectra. The origin of this feature remains debated.…
This paper reviews the effects of general relativity in an X-ray spectrum reflected from a cold matter accreting onto a black hole. The spectrum consists of the iron K$\alpha$ line and the Compton reflection. We sketch the overall picture…
We present detailed broadband X-ray spectral variability of a Seyfert 1 galaxy 1H~0419--577 based on an archival \suzaku{} observation in July 2007, a new \suzaku{} observation performed in January 2010 and the two latest \xmm{}…
Numerical simulations of the interiors of radiation dominated accretion disks show that significant density inhomogeneities can be generated in the gas. Here, we present the first results of our study on X-ray reflection spectra from such…
The broad X-ray iron line, detected in many active galactic nuclei, is likely to be produced by fluorescence from the X-ray illuminated central parts of an accretion disc close to a supermassive black hole. The time-averaged shape of the…
Reflection of light from surfaces is a very common, but complex phenomenon not only in science and technology, but in every day life. The underlying basic optical principles have been developed within the last five centuries using visible…
We compute the X-ray spectra produced by non-static coronae atop accretion discs around black holes and neutron stars. The hot corona is radiatively coupled to the underlying disc (the reflector) and generates an X-ray spectrum which is…
We present a comprehensive study of the emission spectra from accreting sources. We use our new reflection code to compute the reflected spectra from an accretion disk illuminated by X-rays. This set of models covers different values of…
In the disk-corona model, the X-ray spectrum of a stellar-mass black hole in an X-ray binary is characterized by three components: a thermal component from a thin and cold accretion disk, a Comptonized component from a hot corona, and a…
We present an analysis of XMM-Newton observations of eleven Seyfert galaxies that appear to be missing a broad iron K alpha line. These objects represent a challenge to the established paradigm for active galactic nuclei, where a relatively…
We apply a reflection-dominated model to the second XMM-Newton observation of the Narrow Line Seyfert 1 galaxy 1H 0707-495. As in the first XMM-Newton observation a sharp spectral drop is detected with energy that has shifted from 7 keV to…
The innermost regions of accretion disks around black holes are strongly irradiated by X-rays that are emitted from a highly variable, compact corona, in the immediate vicinity of the black hole. The X-rays that are seen reflected from the…
Relativistic reflection features are commonly observed in the X-ray spectra of stellar-mass and supermassive black holes and originate from illumination of the inner part of the accretion disk by a hot corona. All the available relativistic…
We study the effect of returning radiation on the shape of the X-ray reflection spectrum in the case of thin accretion disks. We show that the returning radiation mainly influences the observed reflection spectrum for a large black hole…
We analyse a long archival XMM-Newton observation of the narrow-line Seyfert 1 galaxy Ton S180, using the latest reflection models to explore the high quality X-ray spectrum. We find that the iron line is relatively narrow and sharp, and…
The current status of understanding of the X-ray emission from Seyfert galaxies involves Comptonization of soft photons by hot subrelativistic electrons. After briefly reviewing the early theoretical basis for the presence of hot optically…
Current models of the spectrum of X-rays reflected from accretion disks around black holes and other compact objects are commonly calculated assuming that the density of the disk atmosphere is constant within several Thomson depths from the…
We present angle-dependent, broad-band intensity spectra from accretion disks around black holes of 10 M$_\odot$. In our computations disks are assumed to be slim, which means that the radial advection is taken into account while computing…
We have calculated the relativistic reflection component of the X-ray spectra of accretion disks in active galactic nuclei (AGN). Our calculations have shown that the spectra can be significantly modified by the motion of the accretion flow…