Yuzuru Tawara

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We present the results from a detailed ASCA/ROSAT X-ray study of three distant, massive cooling flows; Zwicky 3146 (z = 0.291), Abell 1835 (z = 0.252) and E1455+223 (Zwicky 7160; z = 0.258). Using multiphase models fitted to the ASCA spectra, we determine values for the temperature, metallicity, luminosity and cooling rates in the clusters. These results(More)
Amygdaloid kindling is a model of human temporal lobe epilepsy, in which excitability in limbic structures is permanently enhanced by repeated stimulations. We report here dendritic aberrations occurring in mice following kindled-seizures. Adult mice received a biphasic square wave pulse [495+/-25.5 (S.E.M.) microA 60 Hz, 200 micros duration, for 2 s](More)
Sialic acids play important roles in various biological functions. In the brain, evidence suggests that sialylation of glycoproteins and glycolipids affects neural plasticity. While the 18 sialyltransferase isoenzymes (STs) identified to date synthesize individual sialyl-oligosaccharide structures, they each exhibit activity toward more than one substrate(More)
We have observed the Sunyaev–Zel'dovich effect in a sample of five moderate-redshift clusters with the Ryle Telescope, and used them in conjunction with X-ray imaging and spectral data from ROSAT and ASCA to measure the Hubble constant. This sample was chosen with a strict X-ray flux limit using both the BCS and NORAS cluster catalogues to be well above the(More)
We present new Ryle Telescope (RT) observations of the Sunyaev Zel'dovich (SZ) decrement from the cluster A773. The field contains a number of faint radio sources that required careful subtraction. We use ASCA observations to measure the gas temperature and a ROSAT HRI image to model the gas distribution. Normalising the gas distribution to fit the RT(More)
Most of cosmic baryons predicted by the big-bang nucleosynthesis has evaded the direct detection. Recent numerical simulations indicate that approximately 30 to 50 percent of the total baryons in the present universe is supposed to take a form of warm/hot intergalactic medium (WHIM) whose X-ray continuum emission is very weak. To identify those missing(More)
Using ASCA data, we have measured the electron temperature in Abell 2163 out to 1.5 h −1 Mpc (3/4 of the virial radius, or 10a x , where a x is the X-ray core-radius) from the center, in three radial bins. The obtained temperatures are 12.2 −0.9 keV in the 0–3 a x (0–3.5 ′), 3–6 a x and 6–13 a x spherical shells, respectively 5. Formally applying the(More)
The MIT Faculty has made this article openly available. Please share how this access benefits you. Your story matters. Abstract ORIGIN is a proposal for the M3 mission call of ESA aimed at the study of metal creation from the epoch of cosmic dawn. Using high-spectral resolution in the soft X-ray band, ORIGIN will be able to identify the physical conditions(More)
The core region of the Shapley Supercluster is dominated by three rich Abell clusters and two poor clusters. Since these member clusters are expected to be evolving rapidly in comparison to nonmember clusters because of the high merging rate, it is important to study the member clusters for understanding of the cluster evolution. Since the spatial(More)