We present the design parameters, production process, and in-flight performance of the X-ray telescope (XRT) onboard Suzaku. The imaging capability is significantly improved over the ASCA XRT, which had half-power diameters of ${3\rlap {.}{}^{\mathrm {\prime }}6}$, to ${1\rlap {.}{}^{\mathrm {\prime }}8}$–${2\rlap {.}{}^{\mathrm {\prime }}3}$ for all four XRT-I modules. The optical axes are found to be distributed within a radius of ${1\rlap {.}{}^{\mathrm {\prime }}3}$, which makes the observation efficiency of all the XRTs more than 97% at the XIS-default observing position. The vignetting over the XIS field of view predicted via ray-tracing coincides with that measured for observations of the Crab Nebula to within $\sim 10\%$. Contemporaneous fits of a power law to all of the XIS spectra of the Crab Nebula taken at the two standard observing positions (XIS/HXD-default positions) gives a flux consistent with that obtained by Toor and Seward (1974, AJ, 79, 995) to within $\sim 2\%$. The pre-collimator on the top of each XRT module successfully reduces the intensity of the stray light from the $20'$ and $50'$-off directions down to the level of pre-flight expectations.

A fast rotating magnetized white dwarf, AEAquarii, was observed with Suzaku, in 2005 October–November and 2006 October with exposures of 53.1 and 42.4 ks, respectively. In addition to clear spin modulation in the 0.5–10 keV band of the XIS data at the barycentric period of 33.0769$\pm$0.0001 s, the 10–30 keV HXD data in the second half of the 2005 observation also showed statistically significant periodic signals at a consistent period. On that occasion, the spin-folded HXD light curve exhibited two sharp spikes separated by $\sim$0.2 cycles in phase, in contrast to approximately sinusoidal profiles observed at energies below $\sim$4 keV. The folded 4–10 keV XIS light curves are understood to be a superposition of those two types of pulse profiles. The phase-averaged 1.5–10 keV spectra can be reproduced by two thermal components with temperatures of $2.90_{-0.16}^{+0.20}$keV and 0.53${\;}_{-0.13}^{+0.14}$keV, but the 12–25 keV HXD data show a significant excess above the extrapolated model. This excess can be explained by either a power-law model with a photon index of $1.12_{-0.62}^{+0.63}$ or a third thermal component with a temperature of 54${\;}_{-47}^{+26}$keV. At a distance of 102 pc, the 4–30 keV luminosities of the thermal and the additional components become $1.7_{-0.6}^{+1.3}$ and 5.3${\;}_{-0.3}^{+15.3}$$\times10^{29}$ergs$^{-1}$, respectively. The latter corresponds to 0.09% of the spin-down energy of the object. Possible emission mechanisms of the hard pulsations are discussed, including non-thermal ones, in particular.

The bubble effects on the resistivity of solution under various conditions of electrolysis was examined with a rectangular cell, in which hydrogen evolution took place from a stainless steel cathode in dilute caustic soda solution. The resistivity of electrolyte containing hydrogen bubbles was a function of the current density, the operating temperature, the flow rate of solution, and the geometry of channel. An experimental equation was obtained.

We present results from the Suzaku observations of the dwarf nova SS Cyg in quiescence and outburst in 2005 November. High sensitivity of the HXD PIN and high spectral resolution of the XIS enable us to determine plasma parameters with unprecedented precision. The maximum temperature of the plasma in quiescence 20.4 +4.0 −2.6 (stat.)±3.0(sys.) keV is significantly higher than that in outburst 6.0 +0.2 −1.3 keV. The elemental abundances are close to the solar ones for the medium-Z elements (Si, S, Ar) whereas they decline both in lighter and heavier elements, except for that of carbon which is 2 solar at least. The solid angle of the reflector subtending over an optically thin thermal plasma is Ω Q /2π = 1.7 ± 0.2 (stat.) ± 0.1 (sys.) in quiescence. A 6.4 keV iron Kα line is resolved into narrow and broad components. These facts indicate that both the white dwarf and the accretion disk contribute to the reflection. We consider the standard optically thin boundary layer as the most plausible picture for the plasma configuration in quiescence. The solid angle of the reflector in outburst Ω O /2π = 0.9 +0.5 −0.4 and a broad 6.4 keV iron line indicate that the reflection in outburst originates from the accretion disk and an equatorial accretion belt. The broad 6.4 keV line suggests that the optically thin thermal plasma is distributed on the accretion 1 arXiv:0809.3559v2 [astro-ph] 8 Oct 2008 disk like solar coronae.