The XIS is an X-ray Imaging Spectrometer system, consisting of state-of-the-art charge-coupled devices (CCDs) optimized for X-ray detection, camera bodies, and control electronics. Four sets of XIS sensors are placed at the focal planes of the grazing-incidence, nested thin-foil mirrors (XRT: X-Ray Telescope) onboard the Suzaku satellite. Three of the XIS sensors have front-illuminated CCDs, while the other has a back-illuminated CCD. Coupled with the XRT, the energy range of 0.2-12 keV with energy resolution of 130 eV at 5.9 keV, and a field of view of 18 × 18 are realized. Since the Suzaku launch on 2005 July 10, the XIS has been functioning well.

We have developed a framework for the Monte-Carlo simulation of the X-Ray Telescopes (XRT) and the X-ray Imaging Spectrometers (XIS) onboard Suzaku, mainly for the scientific analysis of spatially and spectroscopically complex celestial sources. A photon-by-photon instrumental simulator is built on the ANL platform, which has been successfully used in ASCA data analysis. The simulator has a modular structure, in which the XRT simulation is based on a ray-tracing library, while the XIS simulation utilizes a spectral "Redistribution Matrix File" (RMF), generated separately by other tools. Instrumental characteristics and calibration results, e.g., XRT geometry, reflectivity, mutual alignments, thermal shield transmission, build-up of the contamination on the XIS optical blocking filters (OBF), are incorporated as completely as possible. Most of this information is available in the form of the FITS (Flexible Image Transport System) files in the standard calibration database (CALDB). This simulator can also be utilized to generate an "Ancillary Response File" (ARF), which describes the XRT response and the amount of OBF contamination. The ARF is dependent on the spatial distribution of the celestial target and the photon accumulation region on the detector, as well as observing conditions such as the observation date and satellite attitude. We describe principles of the simulator and the ARF generator, and demonstrate their performance in comparison with in-flight data.

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.

We present X-ray proper-motion measurements of the forward shock and reverse-shocked ejecta in Tycho's supernova remnant, based on three sets of archival Chandra data taken in 2000, 2003, and 2007. We find that the proper motion of the edge of the remnant (i.e., the forward shock and protruding ejecta knots) varies from 0 ′′ .20 yr −1 (expansion index m = 0.33, where R = t m ) to 0 ′′ .40 yr −1 (m = 0.65) with azimuthal angle in 2000-2007 measurements, and 0 ′′ .14 yr −1 (m = 0.26) to 0 ′′ .40 yr −1 (m = 0.65) in 2003-2007 measurements. The azimuthal variation of the proper motion and the average expansion index of ∼0.5 are consistent with those derived from radio observations. We also find proper motion and expansion index of the reverse-shocked ejecta to be 0 ′′ .21-0 ′′ .31 yr −1 and 0.43-0.64, respectively. From a comparison of the measured m-value with Type Ia supernova evolutionary models, we find a pre-shock ambient density around the remnant of 0.2 cm −3 .

We introduce a deep (670 ks) X-ray survey of the entire SN 1006 remnant from the Chandra X-ray Observatory, together with a deep Hα image of SN 1006 from the 4m Blanco telescope at CTIO. Comparison with Chandra images from 2003 gives the first measurement of the X-ray proper motions around the entire periphery, carried out over a nine-year baseline. We find that the expansion velocity varies significantly with azimuth. The highest velocity of ∼ 7400 km s −1 (almost 2.5 times that in the NW) is found along the SE periphery, where both the kinematics and the spectra indicate that most of the X-ray emission stems from ejecta that have been decelerated little, if at all. Asymmetries in the distribution of ejecta are seen on a variety of spatial scales. Si-rich ejecta are especially prominent in the SE quadrant, while O and Mg are more uniformly distributed, indicating large-scale asymmetries arising from the explosion itself. Neon emission is strongest in a sharp filament just behind the primary shock along the NW rim, where the pre-shock density is highest. Here the Ne is likely interstellar, while Ne within the shell may include a contribution from ejecta. Within the interior of the projected shell we find a few isolated "bullets" of what appear to be supernova ejecta that are immediately preceded by bowshocks seen in Hα, -2features that we interpret as ejecta knots that have reached relatively dense regions of the surrounding interstellar medium, but that appear in the interior in projection. Recent three-dimensional hydrodynamic models for Type Ia supernovae display small-scale features that strongly resemble the ones seen in X-rays in SN 1006; an origin in the explosion itself or from subsequent hydrodynamic instabilities both remain viable options. We have expanded the search for precursor X-ray emission ahead of a synchrotron-dominated shock front, as expected from diffusive shock acceleration theory, to numerous regions along both the NE and SW rims of the shell. Our data require that a precursor be thinner than about 3 , and fainter than about 5% of the post-shock peak. These limits suggest that the magnetic field is amplified by a factor of 7 or more in a narrow precursor region, promoting diffusive particle acceleration.Subject headings: ISM: individual (SN 1006) -ISM: kinematics and dynamics -supernovae: individual (SN 1006) -supernova remnants -X-rays: individual (SN1006) -X-rays: ISM