Anada, Takayasu, Ebisawa, Ken, Dotani, Tadayasu, Bamba, Aya
We present the ASCA and Suzaku studies of the TeV source HESS J1837--069, which has not been identified in other wave-lengths. We confirm the presence of two X-ray sources in the Suzaku XIS image, AX...
Uchiyama, Hideki, Ozawa, Midori, Matsumoto, Hironori, Tsuru, Takeshi Go, Koyama, Katsuji, Kimura, Masashi, ...
The charge transfer inefficiency (CTI) of the X-ray CCDs on board the Suzaku satellite (X-ray Imaging Spectrometers; XIS) has increased since the launch due to radiation damage, and the energy...
Ozawa, Midori, Uchiyama, Hideki, Matsumoto, Hironori, Nakajima, Hiroshi, Koyama, Katsuji, Tsuru, Takeshi Go, ...
The X-ray Imaging Spectrometer (XIS) on board the Suzaku satellite is an X-ray CCD camera system that has superior performance such as a low background, high quantum efficiency, and good energy...
Miyakawa, Takehiro, Yamaoka, Kazutaka, Homan, Jeroen, Saito, Koji, Dotani, Tadayasu, Yoshida, Atsumasa, ...
We have analyzed 200 Rossi X-ray Timing Explorer observations of the black hole candidate GX 339--4, all from the bright hard state periods between 1996 and 2005. Purpose of our study is to...
Reproducibility of Non-X-ray Background for the X-ray Imaging Spectrometer aboard Suzaku (2008)
Tawa, Noriaki, Hayashida, Kiyoshi, Nagai, Masaaki, Nakamoto, Hajime, Tsunemi, Hiroshi, Yamaguchi, Hiroya, ...
One of the advantages of the X-ray Imaging Spectrometer (XIS) system on board Suzaku is its low and stable non-X-ray background (NXB). In order to make the best use of this advantage, modeling the...
Suzaku Results on Cygnus X-1 in the Low/Hard State (2008)
Makishima, Kazuo, Takahashi, Hiromitsu, Yamada, Shin'ya, Done, Chris, Kubota, Aya, Dotani, Tadayasu, ...
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 x 10^37 erg/s. The XIS...
Suzaku Observation of the Anomalous X-ray Pulsar CXOU J164710.2--455216 (2007)
Naik, Sachindra, Dotani, Tadayasu, Kawai, Nobuyuki, Kokubun, Motohide, Anada, Takayasu, Morii, Mikio, ...
Suzaku TOO observation of the anomalous X-ray pulsar CXOU J164710.2-455216 was performed on 2006 September 23--24 for a net exposure of 38.8 ks. During the observation, the XIS was operated in 1/8...
In Orbit Timing Calibration of the Hard X-Ray Detector on Board Suzaku (2007)
Terada, Yukikatsu, Enoto, Teruaki, Miyawaki, Ryouhei, Ishisaki, Yoshitaka, Dotani, Tadayasu, Ebisawa, Ken, ...
The hard X-ray detector (HXD) on board the X-ray satellite Suzaku is designed to have a good timing capability with a 61 $\mu$s time resolution. In addition to detailed descriptions of the HXD timing...
Suzaku Observations of Hercules X-1 : Measurements of the Two Cyclotron Harmonics (2007)
Enoto, Teruaki, Makishima, Kazuo, Terada, Yukikatsu, Mihara, Tatehiro, Nakazawa, Kazuhiro, Ueda, Tsuyoshi, ...
The accretion-powered pulsar Her X-1 was observed with Suzaku twice in its main-on state, on 2005 October 5-6 and 2006 March 29-30, for a net exposure of 30.5 ks and 34.4 ks, respectively. In the...
Low/Hard State Spectra of GRO J1655-40 Observed with Suzaku (2007)
Takahashi, Hiromitsu, Fukazawa, Yasushi, Mizuno, Tsunefumi, Hirasawa, Ayumi, Kitamoto, Shunji, Sudoh, Keisuke, ...
The Galactic black-hole binary GRO J1655$-$40 was observed with Suzaku on 2005 September 22--23, for a net exposure of 35 ks with the X-ray Imaging Spectrometer (XIS) and 20 ks with the Hard X-ray...
The X-ray Pulse Profile of BG CMi (2007)
Choi, Chul-Sung, Dotani, Tadayasu, Kim, Yonggi, Ryu, Dongsu
We present an analysis of the X-ray data of a magnetic cataclysmic variable, BG CMi, obtained with ROSAT in March 1992 and with ASCA in April 1996. We show that four peaks clearly exist in the X-ray...
Miyakawa, Takehiro G., Yamaoka, Kazutaka, Yoshida, Atsumasa, Saito, Koji, Dotani, Tadayasu, Inoue, Hajime
We have analyzed the 171 RXTE data sets of the black hole candidate GX 339-4 in the low/hard state during its 1996--2005 outburst. All the broadband spectra were successfully modeled by a simple...
Kubota, Aya, Dotani, Tadayasu, Cottam, Jean, Kotani, Taro, Done, Chris, Ueda, Yoshihiro, ...
We present the results of six Suzaku observations of the recurrent black hole transient 4U1630-472 during its decline from outburst from February 8 to March 23 in 2006. All observations show the...
A Flare of AE Aquarii Observed with XMM-Newton (2006)
Choi, Chul-Sung, Dotani, Tadayasu
We present the results of analyzing the XMM-Newton data obtained in 2001 November 7 - 8. A flare is observed simultaneously in X-ray and UV together with a quiescence. We find that during the flare...
Origin of the "Disk-Line" Feature in the X-Ray Energy Spectrum of a Seyfert Galaxy, NGC4151 (2002)
Takahashi, Kazuki, Inoue, Hajime, Dotani, Tadayasu
We have studied the origin of the broad and skewed feature at 4.5-7.5 keV in the energy spectra of NGC4151 using the ASCA and RXTE data. The feature consists of a narrow peak at 6.4 keV and a broad...
Choi, Chul-Sung, Dotani, Tadayasu, Chang, Heon-Young, Yi, Insu
We have studied the long-term X-ray light curve (2$-$10 keV) of the luminous Seyfert 1 galaxy MCG-2-58-22 by compiling data, from various X-ray satellites, which together cover more than 20 years. We...
Wijnands, Rudy, Kuiper, Lucien, Zand, Jean In 't, Dotani, Tadayasu, Van Der Klis, Michiel, Heise, John
We have observed the millisecond X-ray pulsar SAX J1808.4-3658 on three occasions during its 2000 outburst with the BeppoSAX satellite. The source was highly variable and erratic during this...
On the X-ray fast-time variability of Sco X-2 (GX 349+2) (2001)
O'Neill, Paul M., Kuulkers, Erik, Sood, Ravi K., Dotani, Tadayasu
We have analysed archived Ginga data on the Z source Sco X-2 (GX349+2). We present the first detailed investigation of its X-ray fast-time variability, as a function of position in the Z track....
Dotani, Tadayasu, Asai, Kazumi, Wijnands, Rudy
The accretion-powered millisecond X-ray pulsar, SAX J1808.4-3658, was observed in quiescence with ASCA in September 1999. We detected a dim X-ray source in the SIS data at the position consistent to...
Observations of Spectral and Time Variabilities from MCG-2-58-22 (2000)
Choi, Chul-Sung, Dotani, Tadayasu, Yi, Insu, Kim, ChulHee
We present results from analysis of the X-ray archive data of MCG-2-58-22, acquired with ROSAT from 1991 to 1993 and with ASCA from 1993 to 1997. By analyzing light curves, we find that MCG-2-58-22...
Kotani, Taro, Ebisawa, Ken, Dotani, Tadayasu, Inoue, Hajime, Nagase, Fumiaki, Tanaka, Yasuo, ...
We have discovered errors in the calculation of some of the Einstein coefficients in Table 5 and some plots in Figure 3. Due to the errors, the square-root section of the curves of growth of Fe xxvi...
The Nature of Ultra-Luminous Compact X-Ray Sources in Nearby Spiral Galaxies (2000)
Makishima, Kazuo, Kubota, Aya, Mizuno, Tsunefumi, Ohnishi, Tomohisa, Tashiro, Makoto, Aruga, Yoichi, ...
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...
A Study of the X-Ray Emission of Magnetic Cataclysmic Variable Ae Aquarii (1999)
Choi, Chul-Sung, Dotani, Tadayasu, Agrawal, P. C.
We report results from analysis of the X-ray observations of AE Aqr, made with Ginga in June 1988 and with ASCA in October 1995. Pulsations are detected clearly with a sinusoidal pulse profile with...
ASCA and Ginga Observations of GX 1+4 (1998)
Kotani, Taro, Dotani, Tadayasu, Nagase, Fumiaki, Greenhill, John G., Pravdo, Steven H., Angelini, Lorella
The X-ray binary pulsar GX 1+4 was observed with Ginga every year from 1987 to 1991, and with ASCA in 1994. During the Ginga observations, GX 1+4 was in the steady spindown phase, while the X-ray...
Rutledge, Robert E., Lewin, Walter H. G., Van Der Klis, Michiel, Van Paradijs, Jan, Dotani, Tadayasu, Vaughan, Brian, ...
By comparing positions on a spectral color-color diagram from 10 black hole candidates (BHCs) observed with Ginga (1354-64, 1826-24, 1630-47, LMC X-1, LMC X-3, GS 2000+25, GS 2023+33, GS 1124-68, Cyg...
X-ray and gamma-ray spectra of Cyg X-1 in the soft state (1997)
Gierlinski, Marek, Zdziarski, Andrzej A., Dotani, Tadayasu, Ebisawa, Ken, Jahoda, Keith, Johnson, W. Neil
We present X-ray/gamma-ray observations of Cyg X-1 in the soft state during 1996 May-June. We analyze ASCA, RXTE and OSSE data. The spectrum consists of soft X-ray blackbody emission of an optically...