We have reanalysed the ASCA X-ray spectrum of the bright symbiotic star CH Cyg, which exhibits apparently distinct hard and soft X-ray components. Our analysis demonstrates that the soft X-ray emission can be interpreted as scattering of the hard X-ray component in a photo-ionised medium surrounding the white dwarf. This is in contrast to previous analyses in which the soft X-ray emission was f...

The element and orbital-specific electronic structure of thin films of the organic material N,N'-ethylene-bis(1,1,1-trifluoropentane-2,4-dioneiminato)-copper(II) (designated as Cu-TFAC) has been studied using a combination of synchrotron radiation-excited resonant X-ray emission spectroscopy, X-ray photoelectron spectroscopy, X-ray absorption spectroscopy and density functional theory calculati...

A list is presented of known extragalactic radio jets which also have associated X-ray emission. The canonical emission processes for the production of X-rays are reviewed and the sources are categorized on the basis of our current understanding. Although it seems clear that the X-ray emission is non-thermal, the two competing processes, synchrotron and inverse Compton emissions, arise from ext...

Evolution of adiabatic remnants of an aspherical supernova explosion in uniform medium are considered. Thermal X-ray emission of such remnants are investigated. It is shown that integral thermal X-ray characteristics (X-ray luminosity and spectrum) of the objects do not allow us to reveal the assymetry in the explosion because these characteristics are close to their Sedov counterparts. Surface...

In about one year, five gamma–ray bursts were simultaneously observed with the Wide Field Cameras and Gamma Ray Burst Monitor aboard the BeppoSAX satellite. From some of them X–ray afterglow emission has been clearly detected with the same satellite. In order to understand how GRB emission is related to the X–ray afterglow, we are performing a systematic study of the spectral properties of thes...

Thanks to its extraordinary brightness, the X-ray afterglow of GRB030329 could be studied by XMM-Newton up to two months after the prompt Gamma-ray emission. We present the results of two XMM-Newton observations performed on May 5 and 29, as well as an analysis of the Rossi-XTE data of the early part of the afterglow, discussing in particular the stability of the X–ray spectrum and presenting u...

Gadolinium oxysulfide phosphor doped with trivalent terbium have been synthesized using urea homogenous precipitation and followed by sulfurization at 800 °C under argon atmosphere. Structural and morphological of synthesized phosphor powder were characterized by x-ray diffraction (XRD), scanning electron microscopy (SEM) and Fourier transform infrared spectrometry (FT-IR). Hexagonal structure ...

Chandra’s high angular resolution can resolve emission from stellar X-ray binaries out of the diffuse X-ray emission from gaseous atmospheres within elliptical galaxies. Variations in the X-ray binary populations (per unit galaxian optical luminosity) are correlated with variations in the specific frequency of globular clusters in ellipticals. This indicates that X-ray binaries are largely form...

The central engine of Gamma Ray Bursts may live much longer than the duration of the prompt emission. Some evidence of it comes from the presence of strong precursors, post–cursors, and X–ray flares in a sizable fraction of bursts. Additional evidence comes from the fact that often the X–ray and the optical afterglow light curves do not track one another, suggesting that they are two different ...

We examine the possibility that Ultraluminous X-ray sources (ULXs) represent the extreme end of the black hole X-ray binary (XRB) population. Based on their X-ray properties, we suggest that ULXs are persistently in a high/hard spectral state and we propose a new disk–jet model that can accomodate both a high accretion rate and a hard X-ray spectrum. Our model predicts that the modified disk em...