We present a hard X-ray spectrum of unprecedented quality of the Galactic supernova remnant (SNR) W49B obtained with the Suzaku satellite. The spectrum exhibits an unusual structure consisting of a ...saw-edged bump above 8 keV. This bump cannot be explained by any combination of high-temperature plasmas in ionization equilibrium. We firmly conclude that this bump is caused by the strong radiative recombination continuum (RRC) of iron, detected for the first time in a SNR. The electron temperature derived from the bremsstrahlung continuum shape and the slope of the RRC is approx1.5 keV. On the other hand, the ionization temperature derived from the observed intensity ratios between the RRC and Kalpha lines of iron is approx2.7 keV. These results indicate that the plasma is in a highly overionized state. Volume emission measures independently determined from the fluxes of the thermal and RRC components are consistent with each other, suggesting the same origin of these components.
We present the Suzaku spectroscopic study of the Galactic middle-aged supernova remnant (SNR) IC 443. The X-ray spectrum in the 1.75-6.0 keV band is described by an optically thin thermal plasma with ...the electron temperature of approx0.6 keV and several additional Lyman lines. We robustly detect, for the first time, strong radiative recombination continua (RRC) of H-like Si and S around at 2.7 and 3.5 keV. The ionization temperatures of Si and S determined from the intensity ratios of the RRC to He-like Kalpha lines are approx1.0 keV and approx1.2 keV, respectively. We thus find firm evidence for an extremely overionized (recombining) plasma. As the origin of the overionization, a thermal conduction scenario argued in previous work is not favored in our new results. We propose that the highly ionized gas was made at the initial phase of the SNR evolution in dense regions around a massive progenitor, and the low electron temperature is due to a rapid cooling by an adiabatic expansion.
Quasi-hydrostatic cooling of the intracluster gas is studied. In the quasi-hydrostatic model, work done by gravity on the inflow gas with ${\rm d}P \neq 0$, where P is the gas pressure, is taken into ...account in the thermal balance. The gas flows in from the outer part so as to compensate the pressure loss of the gas undergoing radiative cooling, but the mass flow is so moderate and smooth that the gas is considered to be quasi-hydrostatic. The temperature of the cooling gas decreases toward the cluster center, but, unlike cooling flows with ${\rm d}P = 0$, approaches a constant temperature of ~$1/3$ the temperature of the non-cooling ambient gas. This does not mean that gravitational work cancels out radiative cooling, but means that the temperature of the cooling gas appears to approach a constant value toward the cluster center if the gas maintains the quasi-hydrostatic balance. We discuss the mass flow in quasi-hydrostatic cooling, and compare it with the standard isobaric cooling flow model. We also discuss the implication of $\dot{M}$ for the standard cooling flow model.
We have developed a high-efficiency high-resolution particle-induced x-ray emission (PIXE) system employing a von Hamos-type crystal spectrometer for a chemical state identification of trace elements ...in environmental samples. The energy resolution of the system was determined to be about 0.05% through the observation of Si Kalpha(1,2) x rays (1.74 keV) from elemental silicon. The throughput efficiency of the system was also evaluated quasitheoretically to be 1.6x10(-7) counts/incident proton for Si Kalpha(1,2) emission. To demonstrate a chemical state analysis using the high-resolution PIXE system, Si Kalpha(1,2) and Kbeta x-ray spectra for SiC, Si(3)N(4), and SiO(2) were measured and compared. The observed chemical shifts of the Si Kalpha(1,2) peaks for SiC, Si(3)N(4), and SiO(2) relative to elemental silicon were 0.20, 0.40, and 0.55 eV, respectively. The tendency of these shifts were well explained by the effective charges of the silicon atoms calculated by a molecular orbital method.
Abstract
Background
The mid-diastolic L wave is recorded as mid-diastolic mitral forward flow with conventional Doppler echocardiography. L wave is occasionally detected in heart failure (HF) ...patients but its mechanism of occurrence is still unknown. It is hypothesized that L wave was induced by a positive atrioventricular gradient caused by left atrial filling via pulmonary veins, and the magnitude of the L wave is augmented by increasing ventricular stiffness. We speculate that also Left atrium (LA) function will relate with the presence of L wave because the L wave flow occurs passing LA. LA function has been known to have reservoir, booster pump and conduit function. It is reported that LA conduit function related to LA stiffness. The aim of this study is to clarify the association between LA functions and presence of L wave in HF patients.
Methods and results
Eighty two patients who admitted to our hospital for HF were enrolled in this study. We performed echocardiography before discharge. LA speckle-tracking strain was analyzed by an external software program using apical 4 chamber view. Reservoir function was measured as peak strain value at end systole, and booster pump function was measured as the value of atrial contraction. Conduit function was calculated as the difference of the peak value at end systole and atrial contraction. There were 23 patients who had L wave before discharge and 59 patients without L wave. Transmitral E wave (E) and left atrial volume index (LAVI) were higher in patients with L wave than in those without L wave. LA reservoir strain was not different in two groups, but poster pump strain was lower and conduit strain was higher in patients with L wave than those without. LA reservoir strain and booster pump strain weakly correlated with A wave velocity (r=0.39 p=0.004, r=46 p=0.001) and LAVI (r=−0.23 p=0.0383, r=−0.31 p=0.005), but conduit strain had no correlation with A wave (r=0.12 p=0.26) and LAVI (r=−0.04 p=0.67). In multivariate regression analysis for the presence of L wave with A wave velocity, LAVI and LA conduit strain, LA conduit strain remained independent predictors of the presence of L wave (HR 1.12 95% CI 1.04–1.23; p=0.004).
Conclusion
LA conduit function was not correlated with conventional echo parameters of LA function (A wave velocity and LAVI). The presence of L wave was associated with LA conduit strain.
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