Gamma-ray binaries have been uncovered as a new class of Galactic objects in the very high energy sky (> 100 GeV). The three systems known today have hard X-ray spectra (photon index ∼1.5), extended radio emission and a high luminosity in gamma-rays. Recent monitoring campaigns of LSI +61o303 in X-rays have confirmed variability in these systems and revealed a spectral hardening with increasing...

Gamma-ray binaries have been uncovered as a new class of Galactic objects in the very high energy sky (> 100 GeV). The three systems known today have hard X-ray spectra (photon index ∼1.5), extended radio emission and a high luminosity in gamma-rays. Recent monitoring campaigns of LSI +61o303 in X-rays have confirmed variability in these systems and revealed a spectral hardening with increasing...

We have analyzed the long pointed observations of the Z sources in the Rossi X-Ray Timing Explorer (RXTE) public archive to study the high energy emission in those sources. Our analysis is concentrated on the High Energy X–Ray Timing Experiment (HEXTE) waveband, since we are primarily interested in studying the hard X– ray (i.e., E > 20 keV) production in those sources. We give here the prelimi...

the photocatalytic coatings were prepared via incorporating the modified titania nanoparticles into epoxy-based inorganic-organic hybrid coatings. titania nanoparticles were first synthesized from tetra-n-butyl titanate using sol-gel methods by two different calcination treatments, i.e., in mild condition (80°c) and 500°c. the formed anatase nanoparticles were further modified as titania-silica...

Temporal and spectral properties of X-ray rapid variability of Cyg X-1 are studied by an approach of correlation analysis in the time domain on different time scales. The correlation coefficients between the total intensity in 2–60 keV and the hardness ratio of 13–60 keV to 2–6 keV band on the time scale of ∼ 1 ms are always negative in all states. For soft states, the correlation coefficients ...

Temporal and spectral properties of X-ray rapid variability of Cyg X-1 are studied by an approach of correlation analysis in the time domain on different time scales. The correlation coefficients between the total intensity in 2–60 keV and the hardness ratio of 13–60 keV to 2–6 keV band on the time scale of ∼ 1 ms are always negative in all states. For soft states, the correlation coefficients ...

We report the development of a laboratory-based Rowland-circle monochromator that incorporates a low power x-ray (bremsstrahlung) tube source, a spherically bent crystal analyzer, and an energy-resolving solid-state detector. This relatively inexpensive, introductory level instrument achieves 1-eV energy resolution for photon energies of ∼5 keV to ∼10 keV while also demonstrating a net efficien...