With the HEGRA stereoscopic system of imaging atmospheric Cherenkov telescopes, TeV γ-ray emission was detected from the Supernova remnant Cassiopeia A for the first time. The detection has a statistical significance of 5σ. A flux of (5.8 ± 1.2stat ± 1.2syst) × 10−9ph m−2s−1 above 1 TeV is derived. The spectral distribution is consistent with a power law with a differential spectral index −2.5 ...

Recent results in the development of superconductor radiation detectors using superconducting tunnel junctions applied in the energy measurement of X-rays and the detection of heavy ions are reviewed. The energy resolutions of 41 eV, 58 eV, 65 eV, and 129 eV were obtained for 5.9 keV X-rays with 20 20 m, 100 100 m, 200 200 m, and 500 500 m STJs fabricated by introducing a plasma oxidization tec...

Jet models for the high-energy emission of Galactic X-ray binary sources have regained significant interest with detailed spectral and timing studies of the X-ray emission from microquasars, the recent detection by the HESS collaboration of very-high-energy $\gamma$-rays from the microquasar LS~5039, and the earlier suggestion of jet models for ultraluminous X-ray sources observed in many nearb...

We present observations of the Soft γ-ray Repeater SGR 1806−20 taken with the Chandra X-ray Observatory. We identify the X-ray counterpart of SGR 1806−20 based on detection of 7.5-s pulsations. Using three unrelated X-ray sources (and USNO stars) as position references, we are able to determine that the SGR is at α2000 = 18 0839. 32 and δ2000 = −2

We report the discovery of JKCS041, a massive near-infrared selected cluster of galaxies z = 1.9. The cluster was originally discovered using a modified red-sequence method and was also detected in follow-up Chandra data as extended X-ray source. Optical and near-infrared imaging data alone allow us to show that the detection of JKCS041 is as secure as the detections of clusters in the REFLEX s...

We present observations of the Soft γ-ray Repeater SGR 1806−20 taken with the Chandra X-ray Observatory. We identify the X-ray counterpart of SGR 1806−20 based on detection of 7.5-s pulsations. Using three unrelated X-ray sources (and USNO stars) as position references, we are able to determine that the SGR is at α2000 = 18 0839. 32 and δ2000 = −2

Received ; accepted – 2 – ABSTRACT Chandra and XMM-Newton X-ray data reveal that the supersoft X-ray binary CAL 83 exhibits 38.4-minute pulsations at some epochs. These X-ray variations are similar to those found in some novae and are likely to be caused by nonradial pulsations of the white dwarf. This is the first detection of pulsations in a classical supersoft X-ray binary.

The physics potential of the next generation of Gamma Ray Telescopes in exploring the Gamma Ray Horizon is discussed. It is shown that the reduction in the Gamma Ray detection threshold might open the window to use precise determinations of the Gamma Ray Horizon as a function of the redshift to either put strong constraints on the Extragalactic Background Light modeling or to obtain relevant in...

In this article a review on the definition of the X- ray transform and some ofits applications in Nano crystallography is presented. We shall show that the X- raytransform is a special case of the Radon transform on homogeneous spaces when thetopological group E(n)- the Euclidean group - acts on ℝ2 transitively. First someproperties of the Radon transform are investigated then the relationship ...