Related papers: Reflection at large distance from the central engi…
We report on observations of the narrow line Seyfert galaxy NGC 5506 with the Rossi X-ray TIming Explorer. The observations cover a time interval of ~1000 days during which the source showed strong flux and spectral variability. The…
We present an analysis of a sample of Seyfert 1 galaxies observed with Suzaku. The aim of this work is to examine critically the evidence for a relativistic Fe K alpha line in the X-ray spectra of these AGN. The sample was compiled from…
We present a composite 1-10 keV Seyfert 2 X-ray spectrum, derived from ASCA observations of a distance-limited sample of nearby galaxies. All 29 observed objects were detected. Above ~3 keV, the composite spectrum is inverted, confirming…
Before an exoplanet transit, atmospheric refraction bends light into the line of sight of an observer. The refracted light forms a stellar mirage, a distorted secondary image of the host star. I model this phenomenon and the resultant…
The reflection of X-ray radiation produced near a compact object from its stellar companion contributes to the orbital variability of polarization in X-ray binaries. The X-rays are reflected mainly via Thomson scattering resulting in a high…
In this paper, a BeppoSAX observation of the bright Seyfert 2 galaxy NGC6300 is presented. The rapidly variable emission from the active nucleus is seen through a Compton-thin (NH ~ 3x10^23 atomoms/cm/cm) absorber. A Compton-reflection…
We report on a study of the narrow Fe K$\alpha$ line and reflection spectrum in the well-known Seyfert-2 AGN, NGC 4388. X-ray spectra summed from two extensive NICER monitoring campaigns, separated by years, show strong evidence of…
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…
Aims: We analyse a long XMM-Newton spectrum of the narrow-line Seyfert 1 galaxy Mrk 766, using the marked spectral variability on timescales >20ks to separate components in the X-ray spectrum. Methods: Principal components analysis is used…
Through the study of the power spectra of a monochromatic light beam reflected by metallic mirrors, fluctuations in their reflectance is observed. The power spectra were obtained down to a factor $10^{-6}$ below the Standard Quantum Limit,…
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…
We report on a joint ASCA and RXTE observation spanning an $\sim$ 400~ks time interval of the bright Seyfert~1 galaxy MCG--6-30-15. The data clearly confirm the presence of a broad skewed iron line ($W_{K\alpha} \sim$ 266 eV) and Compton…
This is the third article in a series of three dealing with the exploitation of speckle for imaging purposes. In complex media, a fundamental limit is the multiple scattering phenomenon that completely blurs the imaging process in depth.…
We present the analysis of 31 observations of 20 bright Compton thin Seyfert 2s, in the 0.1-200 keV band, performed with the BeppoSAX satellite. The sample consists of all Seyfert 2s in the BeppoSAX public archive, with a 2-10 keV flux…
Cyclotron resonance scattering features are observed in the spectra of some X-ray pulsars and show significant changes in the line energy with the pulsar luminosity. In a case of bright sources, the line centroid energy is anti-correlated…
We present the results of reflection calculations that treat the relevant physics with a minimum of assumptions. The temperature and ionization structure of the top five Thomson depths of an illuminated disc are calculated while also…
The general reflection and refraction laws at the metasurface with the abrupt phase shift were derived by two different methods of Fermat's principle and the boundary conditions respectively. It is found that one or two critical angles for…
X-ray spectral features which are unusually strong in many Narrow-Line Seyfert galaxies are found to be consistent with reflection from strongly ionized matter, providing further evidence of a high accretion rate in these objects and…
The observed hard X-ray (HXR) flux spectrum $I(\epsilon)$ from solar flares is a combination of primary bremsstrahlung photons $I_P(\epsilon)$ with a spectrally modified component from photospheric Compton backscatter of downward primary…
The atmospheres of (exo) planets and moons, as well as reflection nebulae, contain in general independently scattering particles in random orientation and are often supposed to be plane-parallel. Relations are presented for the…