Kazuo Makishima

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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)
High-sensitivity wide-band X-ray spectroscopy is the key feature of the Suzaku X-ray observatory, launched on 2005 July 10. This paper summarizes the spacecraft, in-orbit performance, operations, and data processing that are related to observations. The scientific instruments, the high-throughput X-ray telescopes, X-ray CCD cameras, non-imaging hard X-ray(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)
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 erg s (assuming a(More)
NGC 1316 (Fornax A) is a radio galaxy with prototypical double lobes, where the magnetic field intensity is accurately measured via the inverse-Compton technique. The radio-emitting electrons in the lobes are inferred to have a synchrotron life time of ∼ 0.1 Gyr. Considering the lobe energetics, we estimate the past nuclear X-ray luminosity of NGC 1316 to(More)
X-ray spectra of black hole binaries in the standard high/soft state were studied comprehensively by using ASCA GIS data, and partially RXTE PCA data. A mathematical disk model was applied to several black hole binaries to see if the observed accretion disk temperature profile was consistent with that expected from the standard accretion disk model. This(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, 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 to 5 × 10 and 7 × 10 erg s cm, respectively.(More)
Studies were made of ASCA spectra of seven ultra-luminous compact X-ray sources (ULXs) in nearby spiral galaxies; M33 X-8 (Takano et al. 1994), M81 X-6 (Fabbiano 1988b; Kohmura et al. 1994; Uno 1997), IC 342 Source 1 (Okada et al. 1998), Dwingeloo 1 X-1 (Reynolds et al. 1997), NGC 1313 Source B (Fabbiano & Trinchieri 1987; Petre et al. 1994), and two(More)
The black-hole binary Cygnus X-1 was observed for 17 ks with the Suzaku X-ray observatory in 2005 October, while it was in a low/hard state with a 0.7–300 keV luminosity of 4.6×1037 erg s. The XIS and HXD spectra, spanning 0.7–400 keV, were reproduced successfully incorporating a cool accretion disk and a hot Comptonizing corona. The corona is characterized(More)
We analyzed the ASCA X-ray data of 40 nearby clusters of galaxies, whose intraclustermedium 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 50 Mpc region in order to avoid any possible abundance gradients and complex(More)