Kazuo Makishima

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The NeXT (New exploration X-ray Telescope), the new Japanese X-ray Astronomy Satellite following Suzaku, is an international X-ray mission which is currently planed for launch in 2013. NeXT is a combination of wide band X-ray spectroscopy (3–80 keV) provided by multi-layer coating, focusing hard X-ray mirrors and hard X-ray imaging detectors, and high(More)
The present paper describes the analysis of multiple RXTE/PCA data of the black hole binary with superluminal jet, XTE J1550 − 564, acquired during its 1999–2000 outburst. The X-ray spectra show features typical of the high/soft spectral state, and can approximately be described by an optically thick disk spectrum plus a power-law tail. Three distinct(More)
The ultraluminous compact X-ray sources (ULXs) generally show a curving spectrum in the 0.7–10 keV ASCA bandpass, which looks like a high temperature analogue of the disk dominated high/soft state spectra seen in Galactic black hole binaries (BHBs) at high mass accretion rates. Several ULXs have been seen to vary, and to make a transition at their lowest(More)
We present initial results from ASCA on the spectrum of the Cosmic X-ray Background from 0.4 to 10 keV. About 250 ksec of deep survey data has been collected from the performance veriication phase of ASCA. About 110 ksec of dark-earth data are used to assess the internal background. A single power-law describes the X-ray background very well in the 1 to 10(More)
We present first results from the ASCA Medium Sensitivity Survey (AMSS; or the GIS catalog project). From the serendipitous fields amounting to 106 deg 2 , we determined the Log N-Log S relations in the 0.7–7 keV and 2–10 keV bands with the best statistical accuracy obtained so far, over the flux range from 1 × 10 −11 to 5 × 10 −14 and 7 × 10 −14 erg s −1(More)
Analysis was made of the multiple RXTE/PCA data on the promised black hole candidate with superluminal jet, GRO J1655 − 40, acquired during its 1996– 1997 outburst. The X-ray spectra can be adequately described by the sum of an optically thick disk spectrum and a power-law. When the estimated 1–100 keV power-law luminosity exceeds 1 × 10 37 erg s −1(More)
We studied a time history of X-ray spectral states of a black-hole candidate, 4U 1630-47, utilizing data from a number of monitoring observations with the Rossi X-Ray Timing Explorer over 1996–2004. These observations covered five outbursts of 4U 1630-47, and most of the data recorded typical features of the high/soft states. We found that the spectra in(More)
We analyzed the ASCA X-ray data of 40 nearby clusters of galaxies, whose intracluster-medium temperature distributes in the range of 0.9–10 keV. We measured the Si and Fe abundances of the intracluster medium, spatially averaging over each cluster, but excluding the central ∼ 0.15h −1 50 Mpc region in order to avoid any possible abundance gradients and(More)
We carried out the first wide-area unbiased survey with the ASCA satellite in the 0.7–10 keV band around a north Galactic-pole region covering a continuous area of 7 deg 2 (Large Sky Survey; LSS). To make the best use of ASCA capability, we developed a new source-detection method where the complicated detector responses are fully taken into account.(More)