TeV γ-ray emission has been recently discovered by Cherenkov telescopes from two microquasars, LS 5039 and LS I +61303. This emission is likely to be produced inside the binary system since in both cases variability with the orbital period of the binary has been discovered. In fact, such emission features have been recently predicted by the inverse Compton (IC) e pair cascade model. In this mod...

We report results from a systematic study of the spectral energy distribution (SED) and spectral evolution of XTE J1550–564 and H 1743–322 in outburst. The jets of both sources have been directly imaged at both radio and X-ray frequencies, which makes it possible to constrain the spectrum of the radiating electrons in the jets. We modelled the observed SEDs of the jet ‘blobs’ with synchrotron e...

We present mid-infrared (4–18μm) observations of the microquasar GRS 1915+105 obtained with ISOCAM, the camera on board the Infrared Space Observatory (ISO), in 1996 April and 1997 October. The first observation probably occurred during a flaring event with oscillating synchrotron emission. The 1997 observation occurred a few days before a major relativistic ejection, during a plateau state of ...

In this research zinc oxide (ZnO) nano-crystalline powders were prepared by sol-gel method using zinc acetate. The ZnO nanoparticles were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), ultraviolet-visible (UV-Vis), Fourier transform infra-red (FT-IR) and energy dispersive X-ray (EDX) spectroscopy. The structure of nanoparticles was studied using XRD pattern. The c...

RXTE, GINGA, and OSSE observations have revealed an intense low-energy γ-ray continuum emission from the Galactic plane, which is commonly interpreted as evidence for the possible existence of a strong flux of low-energy cosmic ray electrons. In this Paper I discuss the scenario of a hadronic origin of the soft Galactic γ-ray continuum through inverse bremsstrahlung. A flux of low-energy cosmic...

Using Chandra observations, we study the X-ray emission of the stellar population in the compact dwarf elliptical galaxy M32. The proximity of M32 allows one to resolve all bright point sources with luminosities higher than 8 × 10 33 erg s −1 in the 0.5–7 keV band. The remaining (unresolved) emission closely follows the galaxy's optical light and is characterized by an emissivity per unit stell...

Diiuse Galactic continuum-ray emission in the 0.75-30 MeV range from the whole sky has been studied using COMPTEL data from the rst 3 years of of the Compton Observatory. The imaging properties of COMPTEL enable spatial analysis of the-ray distribution using model tting. A model based on gas and inverse-Compton distributions in the Galaxy has been used to derive the intensity spectrum of the-ra...

We report the discovery of an X-ray neb-ula associated with the nearby millisecond pulsar PSR J2124−3358. This is the first time that extended emission from a solitary millisecond pulsar is detected. The emission extends from the pulsar to the northwest by ∼ 0.5 arcmin. The spectrum of the nebular emission can be modeled by a power law spectrum with photon index of 2.2 ± 0.4. This is inline wit...

The X-ray emission spectrum of liquid ethanol was calculated using density functional theory and a semiclassical approximation to the Kramers-Heisenberg formula including core-hole-induced dynamics. Our spectrum agrees well with the experimental spectrum. We found that the intensity ratio between the two peaks at 526 and 527 eV assigned as 10a' and 3a″ depends not only on the hydrogen bonding n...

We present Hubble Space Telescope images of the Heiii region surrounding the bright X-ray source in the dwarf irregular galaxy Holmberg II. Using Chandra, we find a position for the X-ray source of α = 08h 19m 28.98s, δ = +70 • 42 ′ 19. ′′ 3 (J2000) with an uncertainty of 0.6 ′′. We identify a bright, point-like optical counterpart centered in the nebula with the X-ray source. The optical magni...