Ground-based gamma-ray astronomy has had a major breakthrough with the impressive results obtained using systems of imaging atmospheric Cherenkov telescopes. Ground-based gamma-ray astronomy has a huge potential in astrophysics, particle physics and cosmology. CTA is an international initiative to build the next generation instrument, with a factor of 5-10 improvement in sensitivity in the 100 GeV-10 TeV range and the extension to energies well below 100 GeV and above 100 TeV. CTA will consist of two arrays (one in the north, one in the south) for full sky coverage and will be operated as open observatory. The design of CTA is based on currently available technology. This document reports on the status and presents the major design concepts of CTA.

The Cherenkov Telescope Array (CTA) is a new observatory for very high-energy (VHE) gamma rays. CTA has ambitions science goals, for which it is necessary to achieve full-sky coverage, to improve the sensitivity by about an order of magnitude, to span about four decades of energy, from a few tens of GeV to above 100 TeV with enhanced angular and energy resolutions over existing VHE gamma-ray observatories. An international collaboration has formed with more than 1000 members from 27 countries in Europe, Asia, Africa and North and South America. In 2010 the CTA Consortium completed a Design Study and started a three-year Preparatory Phase which leads to production readiness of CTA in 2014. In this paper we introduce the science goals and the concept of CTA, and provide an overview of the project. ?? 2013 Elsevier B.V. All rights reserved

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High-sensitivity wide-band X-ray spectroscopy is the key feature of the Suzaku X-ray observatory, launched on 2005 July 10. This paper summarizes the spacecraft, in-orbit performance, operations, and data processing that are related to observations. The scientific instruments, the high-throughput X-ray telescopes, X-ray CCD cameras, non-imaging hard X-ray detector are also described.

We present results obtained from a series of observations of the supernova remnant RX J1713.7−3946 by the Suzaku satellite which cover about two-thirds of the remnant surface. Hard X-rays have been detected from each pointing up to ∼ 40 keV. The hard X-ray spectra are described by power-law functions with photon indices of ∼ 3.0, which are larger than those in the energy region below 10 keV. The combination of the spatially-integrated XIS and HXD spectra clearly reveals a spectral cutoff in the X-ray spectrum which is linked to the maximum energy of accelerated electrons emitting synchrotron radiation. The broad-band coverage of Suzaku observations from 0.4 keV to 40 keV allows us to derive, for the first time, the energy spectrum of parent electrons in the cutoff region. The inferred cutoff energy in the spatially-integrated X-ray spectrum indicates that the electron acceleration in the remnant proceeds close to the Bohm-diffusion limit. We discuss implications of the spectral and morphological properties of Suzaku data in the context of the origin of nonthermal emission. The Suzaku X-ray and the H.E.S.S. TeV gamma-ray data together hardly can be explained within a pure leptonic scenario, unless we introduce an additional component of relativistic electrons with softer energy spectrum. Moreover, the leptonic models require very weak magnetic field which does not agree with the recently discovered filamentary structure and short-term variability features of the X-ray emitting region. The hadronic models with strong magnetic field provide perfect fits to the observed X-ray and TeV gamma-ray spectra through the synchrotron radiation of electrons and p-p interactions of protons, but require special arrangements of model parameters to explain the lack of thermal component of X-ray emission. For the morphology studies, we compare the X-ray an TeV gama-ray surface brightness maps using the Suzaku XIS and the H.E.S.S. data. We confirm the previously reported strong correlation between X-ray and TeV gammaray emission components. At the same time the Suzaku data reveal a deviation from the general tendency, namely, the X-ray emission in the western rim regions appears brighter than expected from the average X-ray to gamma-ray ratio. Subject headings: acceleration of particles -ISM: individual(RX J1713.7−3946) -ISM: supernova remnants -X-rays: ISM

We present a spectral analysis of the Crab Nebula obtained with the Chandra X-ray observatory. The X-ray spectrum is characterized by a power law whose index varies across the nebula. The variation can be discussed in terms of the particle injection from the pulsar in two different directions: the equatorial plane containing the torus and the symmetry axis along the jet. In the equatorial plane, spectra within the torus are the hardest, with a photon index % 1:9, and are almost independent of the surface brightness. At the periphery of the torus, the spectrum gradually softens in the outer, lower surface brightness regions, up to % 3:0. This indicates that synchrotron losses become significant to X-ray-emitting particles at the outer boundary of the torus. We discuss the nature of the torus, incorporating information from observations at other wavelengths. Spectral variations are also seen within the southern jet. The core of the jet is the hardest, with % 2:0, and the outer sheath surrounding the core becomes softer with up to 2.5 at the outermost part. Based on the similarity between the spectra of the jet core and the torus, we suggest that the electron spectra of the particles injected from the pulsar are also similar in these two different directions. The brightness ratio between the near and far sides of the torus can be explained by Doppler boosting and relativistic aberration; however, the observed ratio cannot be derived from the standard weakly magnetized pulsar wind model. We also found a site where an optical filament comprising supernova ejecta is absorbing the soft X-ray emission (<2 keV).

Objective:This study aimed to examine a detailed breakdown of costs (absenteeism, presenteeism, and medical/pharmaceutical expenses), of the employees in four pharmaceutical companies in Japan.Methods:This is a cross-sectional study. Absenteeism and presenteeism were measured by a self-administered questionnaire for workers, and their costs were estimated using the human capital approach. Presenteeism was evaluated by the degree affected quality and quantity of work. Medical and pharmaceutical expenses were obtained by insurance claims.Results:The monetary value due to absenteeism was $520 per person per year (11%), that of presenteeism was $3055 (64%), and medical/pharmaceutical expenses were $1165 (25%). Two of the highest total cost burdens from chronic illness were related to mental (behavioral) health conditions and musculoskeletal disorders.Conclusion:A total cost approach can help employers set priorities for occupational health, safety, and population health management initiatives.

High-resolution X-ray spectroscopy with Hitomi was expected to resolve the origin of the faint unidentified » E 3.5 keV emission line reported in several low-resolution studies of various massive systems, such as galaxies and clusters, including the Perseus cluster. We have analyzed the Hitomi first-light observation of the Perseus cluster. The emission line expected for Perseus based on the XMM-Newton signal from the large cluster sample under the dark matter decay scenario is too faint to be detectable in the Hitomi data. However, the previously reported 3.5 keV flux from Perseus was anomalously high compared to the sample-based prediction. We find no unidentified line at the reported high flux level. Taking into account the XMM measurement uncertainties for this region, the inconsistency with Hitomi is at a 99% significance for a broad dark matter line and at 99.7% for a narrow line from the gas. We do not find anomalously high fluxes of the nearby faint K line or the Ar satellite line that were proposed as explanations for the earlier 3.5 keV detections. We do find a hint of a broad excess near the energies of high-n transitions of S XVI (  E 3.44 keV rest-frame)-a possible signature of charge exchange in the molecular nebula and another proposed explanation for the unidentified line. While its energy is consistent with XMM pn detections, it is unlikely to explain the MOS signal. A confirmation of this interesting feature has to wait for a more sensitive observation with a future calorimeter experiment.