Spectral Variation of the Seyfert 1 Galaxy MCG-6-30-15 observed with Suzaku (2009)
Miyakawa, Takehiro, Ebisawa, Ken, Terashima, Yuichi, Tsuchihashi, Fuminori, Inoue, Hajime, Zycki, Piotr
We have investigated spectral variation of the Seyfert 1 galaxy MCG-6-30-15 observed with Suzaku in January 2006 for three separate periods spreading over fourteen days. We found that the...
The MAXI Mission on the ISS: Science and Instruments for Monitoring All Sky X-Ray Images (2009)
Matsuoka, Masaru, Kawasaki, Kazuyoshi, Ueno, Shiro, Tomida, Hiroshi, Kohama, Mitsuhiro, Suzuki, Motoko, ...
The MAXI (Monitor of All-sky X-ray Image) mission is the first astronomical payload to be installed on the Japanese Experiment Module-Exposed Facility (JEM-EF) on the ISS. It is scheduled for launch...
Suzaku X-Ray Study of an Anomalous Source XSS J12270-4859 (2009)
Saitou, Kei, Tsujimoto, Masahiro, Ebisawa, Ken, Ishida, Manabu
We report the results of the Suzaku X-ray observation of XSS J12270-4859, one of the hard X-ray sources in the INTEGRAL catalogue. The object has been classified as an intermediate polar (IP) by...
Iron emission lines on the galactic ridge observed with Suzaku (2009)
Yamauchi, Shigeo, Ebisawa, Ken, Tanaka, Yasuo, Koyama, Katsuji, Matsumoto, Hironori, Yamasaki, Noriko Y., ...
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...
A Simple Comptonization Model (2008)
Steiner, James F., Narayan, Ramesh, McClintock, Jeffrey E., Ebisawa, Ken
We present an empirical model of Comptonization for fitting the spectra of X-ray binaries. This model, "simpl", has been developed as a package implemented in XSPEC. With only two free parameters,...
Iron Emission Lines on the Galactic Ridge Observed with Suzaku (2008)
Yamauchi, Shigeo, Ebisawa, Ken, Tanaka, Yasuo, Koyama, Katsuji, Matsumoto, Hironori, Yamasaki, Noriko Y., ...
In order to elucidate origin of the Galactic Ridge X-ray Emission, we analyzed Suzaku data taken at various regions along the Galactic plane and studied their Fe-K emission line features. Suzaku...
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...
Spectral study of the galactic ridge X-ray emission with Suzaku (2008)
Ebisawa, Ken, Yamauchi, Shigeo, Tanaka, Yasuo, Koyama, Katsuji, Ezoe, Yuichiro, Bamba, Aya, ...
Spectral Study of the Galactic Ridge X-ray Emission with Suzaku (2007)
Ebisawa, Ken, Yamauchi, Shigeo, Tanaka, Yasuo, Koyama, Katsuji, Ezoe, Yuichiro, Bamba, Aya, ...
We have observed a typical Galactic plane field at (l,b) = (28.46d, -0.20d) with Suzaku for 100 ksec to carry out a precise spectral study of the Galactic Ridge X-ray Emission (GRXE). The field is...
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 Detection of Extended/Diffuse Hard X-Ray Emission from the Galactic Center (2007)
Yuasa, Takayuki, Tamura, Ken-ichi, Nakazawa, Kazuhiro, Kokubun, Motohide, Makishima, Kazuo, Bamba, Aya, ...
Five on-plane regions within +/- 0.8deg of the Galactic center were observed with the Hard X-ray Detector (HXD) and the X-ray Imaging Spectrometer (XIS) onboard Suzaku. From all regions, significant...
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...
Discovery of a new X-ray transient source in the Scutum region with Suzaku (2007)
Yamauchi, Shigeo, Ebisawa, Ken, Bamba, Aya, Ishida, Manabu, Iwasawa, Kazushi, Tanaka, Yasuo, ...
The X-ray observatory Suzaku (2007)
Mitsuda, Kazuhisa, Bautz, Mark, Inoue, Hajime, Kelley, Richard L., Koyama, Katsuji, Kunieda, Hideyo, ...
Hard X-ray investigation of the galactic center region with Suzaku (2007)
Kokubun, Motohide, Yuasa, Takayuki, Tamura, Ken-ichi, Makishima, Kazuo, Takahashi, Tadayuki, Nakazawa, Kazuhiro, ...
Suzaku spectral study of the galactic ridge X-ray emission (2007)
Ebisawa, Ken, Yamauchi, Shigeo, Tanaka, Yasuo, Koyama, Katsuji, Suzaku Team
A Stellar-mass Black Hole in the Ultra-luminous X-ray Source M82 X-1? (2006)
Okajima, Takashi, Ebisawa, Ken, Kawaguchi, Toshihiro
We have analyzed the archival XMM-Newton data of the bright Ultra-Luminous X-ray Source (ULX) M82 X-1 with an 105 ksec exposure when the source was in the steady state. Thanks to the high photon...
Do Ultraluminous X-ray Sources Really Contain Intermediate-mass Black Holes? (2006)
Vierdayanti, Kiki, Mineshige, Shin, Ebisawa, Ken, Kawaguchi, Toshihiro
An open question remains whether Ultraluminous X-ray Sources (ULXs) really contain intermediate-mass black holes (IMBHs). We carefully investigated the XMM-Newton EPIC spectra of the four ULXs that...
Kubota, Aya, Ebisawa, Ken, Makishima, Kazuo, Nakazawa, Kazuhiro
X-ray spectra of black hole binaries(BHBs) in the high/soft state were studied comprehensively by using ASCA GIS data, and partially RXTE PCA data. A mathematical disk model was applied to several...
Systematic Search for Short-transients and Pulsation Events from INTEGRAL Survey Data (2004)
Ebisawa, Ken, Kretschmar, Peter, Mowlavi, Nami, Paizis, Ada, Produit, Nicolas, Shaw, Simon, ...
The imaging instruments on board INTEGRAL have wide fields of view and high time resolution. Therefore, they are ideal instruments to search for pulsating sources and/or transient events. We are...
A New View of the Supersoft X-Ray Source Cal 87 Observed with XMM-Newton (2004)
Orio, Marina, Ebisawa, Ken, Heise, John, Hartmann, Wouter
Cal 87 was observed with XMM-Newton in April of 2003. The source shows a rich emission line spectrum, where lines can be identified if they are red-shifted by 700-1200 km/s. These lines seem to have...
High-Energy sources before INTEGRAL -- INTEGRAL reference catalog -- (2003)
Ebisawa, Ken, Bourban, G., Bodaghee, A., Mowlavi, N., Courvoisier, T. J. -L.
We describe the INTEGRAL reference catalog which classifies previously known bright X-ray and gamma-ray sources before the launch of INTEGRAL. These sources are, or have been at least once, brighter...
Ebisawa, Ken, Zycki, Piotr, Kubota, Aya, Mizuno, Tsunefumi, Watarai, Ken-ya
Ultra-luminous Compact X-ray Sources (ULXs) in nearby spiral galaxies and Galactic superluminal jet sources share the common spectral characteristic that they have unusually high disk temperatures...
Ueno, Masaru, Bamba, Aya, Koyama, Katsuji, Ebisawa, Ken
We present the Chandra results of AX J1843.8-0352, a supernova remnant (SNR) recently identified with ASCA. Chandra spatially resolved two components from this SNR: non-thermal and thermal ones. The...
Ebisawa, Ken, Beckmann, V., Courvoisier, T. J. -L., Dubath, P., Kaneda, H., Maeda, Y., ...
We have carried out a deep X-ray observation on a typical Galactic plane region with the Chandra ACIS-I instrument with unprecedented sensitivity and spatial resolution, and detected 274 unidentified...
Ebisawa, Ken, Fujimoto, R., Ueda, Y.
We are systematically analyzing ASCA GIS data taken during the satellite attitude maneuver operation. Our motivation is to search for serendipitous hard X-ray sources and make the ASCA Slew Survey...
The complex X-ray spectrum of the supersoft source MR Vel (2002)
Bearda, Henk, Hartmann, Wouter, Ebisawa, Ken, Heise, John, Kaastra, Jelle, Van Der Meer, Rob, ...
We present the X-ray spectrum of MR Vel/RXJ0925.7-4758 obtained with the Medium Energy Grating spectrometer of the Chandra X-ray Telescope. The simplest models used by earlier authors, stellar...
Chandra Observations of a New Supernova Remnant AX J1843.8-0352/G28.6-0.1 (2002)
Koyama, Katsuji, Ueno, Masaru, Bamba, Aya, Ebisawa, Ken
AX J1843.8-0352 is a new X-ray SNR identified to the radio complex G28.6-0.1 with the ASCA satellite. Chandra discovered two distinct components from this SNR: non-thermal and thin thermal X-ray...
Origin of the Hard X-ray Emission from the Galactic Plane (2001)
Ebisawa, Ken, Maeda, Yoshitomo, Kaneda, Hidehiro, Yamauchi, Shigeo
The Galactic plane is a strong hard x-ray emitter and the emission forms a narrow continuous ridge. The currently known hard x-ray sources are far too few to explain the ridge x-ray emission, and the...
Ebisawa, Ken, Kubota, Aya, Mizuno, Tsunefumi, Zycki, Piotr
The Ultra-luminous Compact X-ray Sources (ULXs) in nearby spiral galaxies and the Galactic super-luminal jet sources share the common spectral characteristic that they have extremely high disk...
Observational Evidence for Strong Disk Comptonization in GRO J1655-40 (2001)
Kubota, Aya, Makishima, Kazuo, Ebisawa, Ken
Analysis was made of the multiple XTE/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...
Gierlinski, Marek, Maciolek-Niedzwiecki, Andrzej, Ebisawa, Ken
We present a general relativistic accretion disc model and its application to the soft-state X-ray spectra of black hole binaries. The model assumes a flat, optically thick disc around a rotating...
ASCA Observation of an "X-ray Shadow" in the Galactic Plane (2000)
The diffuse X-ray background (DXB) emission near the Galactic plane ($l,b \sim 25.6^{\circ},0.78^{\circ}$) has been observed with $ASCA$. The observed region is toward a Galactic molecular cloud...
On the Origin of the Iron K Line in the Spectrum of the Galactic X-ray Background (2000)
Valinia, Azita, Tatischeff, Vincent, Arnaud, Keith, Ebisawa, Ken, Ramaty, Reuven
We propose a mechanism for the origin of the Galactic ridge X-ray background that naturally explains the properties of the Fe K line, specifically the detection of the centroid line energy below 6.7...
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...
Zdziarski, Andrzej A., Poutanen, Juri, Mikolajewska, Joanna, Gierlinski, Marek, Ebisawa, Ken, Johnson, W. Neil
We present X-ray/gamma-ray spectra of the binary GX 339-4 observed in the hard state simultaneously by Ginga and CGRO OSSE during an outburst in 1991 September. The Ginga spectra are well represented...
Thermal/non-thermal model of Cyg X-1 in the soft state (1997)
Gierlinski, Marek, Zdziarski, Andrzej A., Coppi, Paolo S., Poutanen, Juri, Ebisawa, Ken, Johnson, W. N.
We analyze X-ray/gamma-ray observations of Cyg X-1 in the soft state. We find the hybrid thermal/non-thermal model fits the data very well. The significant contribution from the non-thermal electrons...
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...
Simultaneous X-ray and gamma-ray observations of Cyg X-1 in the hard state by Ginga and OSSE (1996)
Gierlinski, Marek, Zdziarski, Andrzej A., Done, Chris, Johnson, W. Neil, Ebisawa, Ken, Ueda, Yoshihiro, ...
We present four X-ray/gamma-ray spectra of Cyg X-1 observed in the hard ('low') state simultaneously by Ginga and GRO/OSSE on 1991 July 6. The 3-30 keV Ginga spectra are well represented by power...
The first simultaneous X-ray/gamma-ray observations of Cyg X-1 by Ginga and OSSE (1995)
Gierlinski, Marek, Zdziarski, Andrzej A., Johnson, W. Neil, Phlips, Bernard F., Ebisawa, Ken, Done, Chris
We present the results of 4 simultaneous observations of Cygnus X-1 by Ginga and OSSE. The X-ray/gamma-ray spectra can be described by an intrinsic continuum and a component due to Compton reflection...
On the Spectral Slopes of Hard X-ray Emission from Black Hole Candidates (1995)
Ebisawa, Ken, Titarchuk, Lev G., Chakrabarti, Sandip K.
Most black hole candidates exhibit characteristic power-law like hard X-ray emission above $\sim$ 10 keV. In the {\em high state}, in which 2 -- 10 keV luminosity is relatively high, the energy index...
Spectral study of black hole candidates observed with Ginga /--Ken Ebisawa. (1991)
Ebisawa, Ken., Uchū Kagaku Kenkyūjo (Japan)
Thesis (Ph. D.)--University of Tokyo, 1991.
EBISAWA, Ken, NONOMURA, Yoshiaki
A Ca2+dependent actin-severing 84K Mr protein prepared from bovine aorta caused four-fold activation of smooth muscle actin-activated myosin ATPase at a 1/102 molar ratio to actin in the presence of...
Contractile and regulatory proteins were prepared from bovine aortic mtima, and actin from bovine stomach smooth and rabbit skeletal muscles. In the desensitized and reconstituted actomyosin system,...
Intimal myosin B considerably retained the Ca2+ in the presence of chlor promazine which inhibited the phosphorylation of myosin light chain. This result suggests that the phosphorylation and...