Taro Kotani

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Microquasars occasionally exhibit massive jet ejections which are distinct from the continuous or quasi-continuous weak jet ejections. Because those massive jet ejections are rare and short events, they have hardly been observed in X-ray so far. In this paper, the first X-ray observation of a massive jet ejection from the microquasar SS 433 with the Rossi(More)
A full band Monte Carlo simulation based on ab initio calculations is presented to investigate high-field carrier transport characteristics. The band structure and the impact ionization rate of wide bandgap semiconductors are calculated based on a quasiparticle selfconsistent GW method. Then, we demonstrate the full band Monte Carlo simulation in diamond to(More)
We present the results of optical panoramic and long-slit spectroscopy of the neb-ula MF16 associated with the Ultraluminous X-ray Source NGC6946 ULX-1. More than 20 new emission lines are identified in the spectra. Using characteristic line ratios we find the electron density n e ∼ 600 cm −3 , electron temperature in the range from ∼ 9 000 K to ∼ 20 000 K(More)
We present the results of six Suzaku observations of the recurrent black hole transient 4U 1630 − 472 during its decline from outburst from February 8 to March 23 in 2006. All observations show the typical high/soft state spectral shape in the 2–50 keV band, roughly described by an optically thick disk spectrum in the soft energy band plus a weak power-law(More)
We present the results from a multiwavelength campaign of GRS 1915+105 performed from 2000 April 16 to 25. This is one of the largest coordinated set of observations ever performed for this source, covering the wide energy band in radio (13.3–0.3 cm), near-infrared (J-H-K), X-rays and Gamma-rays (from 1 keV to 10 MeV). During the campaign GRS 1915+105 was(More)
We report observation results of the super-soft X-ray sources (SSS) CAL87 and RXJ0925.7–4758 with the X-ray CCD cameras (Solid-state Imaging Spectrometer; SIS) on-board the ASCA satellite. Because of the superior energy resolution of SIS (∆E/E ∼ 10% at 1 keV) relative to previous instruments, we could study detailed X-ray spectral structure of these sources(More)
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