Junko Hiraga

Study of Nonthermal Emission from SNR RX J1713.7–3946 with Suzaku

We present results obtained from a series of observations of the supernova remnant RX J1713.7–3946 by Suzaku. Hard X-rays have been detected up to ~40 keV. The hard X-ray spectra are described by a power law with photon indices of ~3.0, which is larger than those below 10 keV. The combination of the spatially integrated XIS and HXD spectra clearly reveals a spectral cutoff which is linked to the maximum energy of accelerated electrons. The broadband coverage of Suzaku allows us to derive, for the first time, the energy spectrum of parent electrons in the cutoff region. The cutoff energy in the X-ray spectrum indicates that the electron acceleration in the remnant proceeds close to the Bohm diffusion limit. We discuss the implications of the spectral and morphological properties of the Suzaku data in the context of the origin of nonthermal emission. The Suzaku X-ray and H.E.S.S. gamma-ray data together hardly can be explained within a pure leptonic scenario. Moreover, the leptonic models require a weak magnetic field, which is inconsistent with the recently discovered X-ray filamentary structures and their short-term variability. The hadronic models with strong magnetic fields provide reasonable fits to the observed spectra, but require special arrangements of parameters to explain the lack of thermal X-ray emission. For morphology studies, we compare the X-ray and TeV gamma-ray surface brightness. We confirm the previously reported strong correlation between X-rays and TeV gamma rays. At the same time, the Suzaku data reveal a deviation from the general tendency, namely, the X-ray emission in the western rims appears brighter than expected from the average X-ray to gamma-ray ratio.

Biomechanical effect of anteriorly directed extraoral forces on the craniofacial complex: a study using the finite element method.

This study was designed to investigate the biomechanical effect of protractive maxillary orthopedic forces on the craniofacial complex by use of the three-dimensional finite element method (FEM). The three-dimensional FEM model was developed on the basis of a dry skull of a young human being. The model consisted of 2918 nodes and 1776 solid elements. Eighteen cranial and facial sutural systems were integrated in the model. An anteriorly directed 1.0-kg force was applied on the buccal surfaces of the maxillary first molars in both a horizontal parallel direction and a 30 degree obliquely downward direction to the functional occlusal plane. The nasomaxillary complex showed a forward displacement with upward and forward rotation in a horizontal protraction case, whereas a downward force produced almost translatory repositioning of the complex in an anterior direction. High stress levels were observed in the nasomaxillary complex and its surrounding structures. However, the pattern of stress distributions within the complex was different in two force systems. A downward protraction force produced relatively uniform stress distributions, indicating the importance of the force direction in determining the stress distributions from various orthopedic forces.

Chandra Observations of Galactic Supernova Remnant Vela Jr.: A New Sample of Thin Filaments Emitting Synchrotron X-Rays

The Galactic supernova remnant (SNR) Vela Jr. (RXxa0J0852.0-4622, G266.6-1.2) shows sharp filamentary structures on its northwestern edge in the hard X-ray band. The filaments are very smooth and located on the extreme outside edge of the remnant. We measured the averaged scale width of the filaments (wu and wd) with excellent spatial resolution with Chandra, and they are on the order of the size of the point-spread function of Chandra on the upstream side and 495 (360-888) on the downstream side. The spectra of the filaments are very hard and have no linelike structure; they were well reproduced with an absorbed power-law model with Γ = 2.67 (2.55-2.77) or a SRCUT model with νroll = 4.3 (3.4-5.3) × 1016xa0Hz under the assumption of p = 0.3. These results imply that the hard X-rays are synchrotron radiation emitted by accelerated electrons, as mentioned previously. Using a correlation between the function ≡ νroll/w and the SNR age, we estimated the distance and the age of Vela Jr.: the estimated distance and age are 0.33 (0.26-0.50)xa0kpc and 660 (420-1400)xa0yr, respectively. These results are consistent with previous reports, implying that the -age relation may be a useful tool for estimating the distance and the age of synchrotron X-ray-emitting SNRs.

Spectral properties of nonthermal X-ray emission from the shell-type SNR RX J1713.7-3946 as revealed by XMM-Newton

We present the results of our morphological and spectral study of the properties of the supernova remnant RXxa0J1713.7-3946 based on data obtained with XMM-Newton . Highly inhomogeneous structures, such as the bright spots, filaments, and dark voids noted by Uchiyama etxa0al. ([CITE]), appear in the entire bright western portion of the shell. In addition two narrow rims are found which run parallel to each other from north to south in the western part of the remnant. No complex structures are seen in the interior region of the remnant. The X-ray spectra everywhere can be well represented by a power-law function with photon index in the range within

How Big Are Charge Clouds inside the Charge-Coupled Device Produced by X-Ray Photons?

Gamma =

Overabundance of Calcium in the Young SNR RX J0852–4622: Evidence of Over-Production of 44Ti

2.0–2.8. A clear difference between spectra of the central dim region and of the bright western portion is seen at lower energies. This difference can be ascribed either to an additional thermal component in the center with electron temperature

Subpixel Spatial Resolution of the X-Ray Charge-Coupled Device Based on the Charge Cloud Shape

kT_{mathrm e}= 0.56~{rm ~keV}

Measurement of quantum efficiency of a charge coupled device

or, alternatively, to an increase in column density by

DIAGNOSTICS OF THE CCD USING THE MESH EXPERIMENT

Delta N_{mathrm H}sim 0.3times 10^{22}~ {rm cm}^{-2}

Direct measurement of sub-pixel structure of the EPIC MOS CCD on-board the XMM/NEWTON satellite

in the western region. In the context of the recent discovery by the NANTEN telescope of a molecular cloud apparently interacting with the western part of the supernova remnant the second possibility seems to be the more likely scenario.