Theoretical Calculation of Cosmic-Ray Solar Semi-Diurnal Variation -Nucleonic Component

Theoretical calculations of the solar semi-diurnal variation expected at 41 stations for the nucleonic component have been made for two types of spectra, the power- and exponential-type. The latitude distribution of the semi-diurnal anisotropy has also been considered of both forms of the cosine- and the square of the cosine-function of the geographic latitude. Calculated results for four cases of the combination of these spectral and latitude dependences are compared. It is found that a difference in the results for the two types of the latitude distribution is appreciably large, particularly in the amplitude at high and very high latitude stations. A tendency is also shown in comparison of the results for the two types of spectral dependences that the calculated values with some higher cut-off rigidity in the power-type spectrum rather corresponds to the values with the rigidity giving the peak intensity in the exponential-type spectrum. Finally the expected relative amplitude and average deflection angle are tabulated for the case where the spectral form is of the exponential-type of R^γexp(-R/R_0) and the latitude distribution has a form of (√3)/2cos^2λ.Article信州大学理学部紀要 5(1): 37-64(1970)departmental bulletin pape

A Prospective Study of Long-term Outcomes in Female Patients with Nonalcoholic Steatohepatitis Using Age- and Body Mass Index-matched Cohorts

In patients with nonalcoholic steatohepatitis (NASH), the prevalence of cirrhosis is higher among women than men, and hepatocellular carcinoma (HCC) develops mainly in the cirrhotic stage among women. However, the long-term outcomes in female patients with NASH have not been fully elucidated, and age, gender and BMI were not simultaneously adjusted in previous studies on the prognosis of NASH. To elucidate the outcomes in female patients with NASH, we prospectively compared NASH patients with advanced fibrosis (advanced NASH) with hepatitis C virus-related advanced fibrosis (advanced CHC) patients and NASH patients with mild fibrosis (mild NASH) using study cohorts that were adjusted for body mass index (BMI) in addition to age. The median follow-up period was 92.5 months. Liver-related complication-free survival was significantly reduced in the advanced NASH group compared to the mild NASH group. No liver-related complications developed in the mild NASH group. The overall survival, liver-related complication- and cardiovascular/cerebrovascular disease-free survival were not significantly different between the advanced NASH and CHC groups. Female patients with NASH and advanced fibrosis may have a less favorable prognosis for liver-related complications than the matched cohorts with NASH and mild fibrosis, but may have a similar prognosis to the matched cohorts with CHC

Discovery of X-Ray-Emitting O-Ne-Mg-Rich Ejecta in the Galactic Supernova Remnant Puppis A

We report on the discovery of X-ray--emitting O-Ne-Mg-rich ejecta in the middle-aged Galactic O-rich supernova remnant Puppis A with Chandra and XMM-Newton. We use line ratios to identify a low-ionization filament running parallel to the northeastern edge of the remnant that requires supersolar abundances, particularly for O, Ne, and Mg, which we interpret to be from O-Ne-Mg-rich ejecta. Abundance ratios of Ne/O, Mg/O, and Fe/O are measured to be ~2, ~2, and <0.3 times the solar values. Our spatially-resolved spectral analysis from the northeastern rim to the western rim otherwise reveals sub-solar abundances consistent with those in the interstellar medium. The filament is coincident with several optically emitting O-rich knots with high velocities. If these are physically related, the filament would be a peculiar fragment of ejecta. On the other hand, the morphology of the filament suggests that it may trace ejecta heated by a shock reflected strongly off the dense ambient clouds near the northeastern rim.Comment: Published onlin

A Suzaku Study of Ejecta Structure and Origin of Hard X-ray Emission in the Supernova Remnant G156.2+5.7

We report an X-ray study of the evolved Galactic supernova remnant (SNR) G156.2+5.7 based on six pointing observations with Suzaku. The remnant's large extent (100\arcmin in diameter) allows us to investigate its radial structure in the northwestern and eastern directions from the apparent center. The X-ray spectra were well fit with a two-component non-equilibrium ionization model representing the swept-up interstellar medium (ISM) and the metal-rich ejecta. We found prominent central concentrations of Si, S and Fe from the ejecta component; the lighter elements of O, Ne and Mg were distributed more uniformly. The temperature of the ISM component suggests a slow shock (610-960 km s$^{-1}$), hence the remnant's age is estimated to be 7,000-15,000 yr, assuming its distance to be $\sim$1.1 kpc. G156.2+5.7 has also been thought to emit hard, non-thermal X-rays, despite being considerably older than any other such remnant. In response to a recent discovery of a background cluster of galaxies (2XMM J045637.2+522411), we carefully excluded its contribution, and reexamined the origin of the hard X-ray emission. We found that the residual hard X-ray emission is consistent with the expected level of the cosmic X-ray background. Thus, no robust evidence for the non-thermal emission was obtained from G156.2+5.7. These results are consistent with the picture of an evolved SNR.Comment: 10 pages 8 figures, accepted for PAS

Possible Charge-Exchange X-Ray Emission in the Cygnus Loop Detected with Suzaku

X-ray spectroscopic measurements of the Cygnus Loop supernova remnant indicate that metal abundances throughout most of the remnant's rim are depleted to about 0.2 times the solar value. However, recent X-ray studies have revealed in some narrow regions along the outermost rim anomalously "enhanced" abundances (up to about 1 solar). The reason for these anomalous abundances is not understood. Here, we examine X-ray spectra in annular sectors covering nearly the entire rim of the Cygnus Loop using Suzaku (21 pointings) and XMM-Newton (1 pointing). We find that spectra in the "enhanced" abundance regions commonly show a strong emission feature at about 0.7 keV. This feature is likely a complex of He-like O K(gamma + delta + epsilon), although other possibilities cannot be fully excluded. The intensity of this emission relative to He-like O Kalpha appears to be too high to be explained as thermal emission. This fact, as well as the spatial concentration of the anomalous abundances in the outermost rim, leads us to propose an origin from charge-exchange processes between neutrals and H-like O. We show that the presence of charge-exchange emission could lead to the inference of apparently "enhanced" metal abundances using pure thermal emission models. Accounting for charge-exchange emission, the actual abundances could be uniformly low throughout the rim. The overall abundance depletion remains an open question.Comment: Published in Ap

The First X-Ray Proper-Motion Measurements of the Forward Shock in the Northeastern Limb of SN 1006

We report on the first X-ray proper-motion measurements of the nonthermally-dominated forward shock in the northeastern limb of SN 1006, based on two Chandra observations taken in 2000 and 2008. We find that the proper motion of the forward shock is about 0.48 arcsec/yr and does not vary around the rim within the ~10% measurement uncertainties. The proper motion measured is consistent with that determined by the previous radio observations. The mean expansion index of the forward shock is calculated to be ~0.54 which matches the value expected based on an evolutionary model of a Type Ia supernova with either a power-law or an exponential ejecta density profile. Assuming pressure equilibrium around the periphery from the thermally-dominated northwestern rim to the nonthermally-dominated northeastern rim, we estimate the ambient density to the northeast of SN 1006 to be about 0.085/cm^3.Comment: Accepted for publication in The Astrophysical Journal Letter

CONTINUOUS MEASUREMENTS OF COSMIC-RAY INTENSITY WITH MULTI-DIRECTIONAL MUON TELESCOPE 50 M.W.E. UNDERGROUND AT MATSUMOTO

A multi-directional muon telescope having an area of 8m² was constructed in a tunnel with a vertical depth of approximately 50 m. w. e. at Matsumoto. Continuous measurements of cosmic-ray intensity have been made since April 7, 1971. A preliminary report is presented concerning the underground site, experimental apparatus, and its arrangement, as well as some examples of experimental data obtained, and analyzed results of cosmic-ray daily variation. Counting-rates are 6 x 10⁴/hr of vertical component for 8 m² area at a depth of ～50 m. w. e., and 3.4 x 10⁴ /hr of N-component at ～42 m. w. e., 0.85 x 10⁴ /hr of S-component at ～92 m. w. e. for each of 6 m² area, 1. 1 x 10⁴ /hr of E-component at ～65 m. w. e., and 1. 55 x 10⁴ /hr of W-component at ～53 m.w.e. for each of 4m² area, inclined at 40° to the vertical. It is found that the observed phases of diurnal and semidiurnal vectors for five components are indicative of the extraterrestrial nature of the daily variation. The observation thus may provide an important information on the modulation of cosmic-ray intensity variation.Article信州大学教養部紀要. 第二部, 自然科学 6: 9-30(1972)departmental bulletin pape