Search Publications
Energy-Scale Calibration of the Suzaku X-Ray Imaging Spectrometer Using the Checker Flag Charge-Injection Technique in Orbit
Dotani, Tadayasu; Miller, Eric D.; Mori, Hideyuki +25 more
The X-ray Imaging Spectrometer (XIS) aboard 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 resolution in the 0.2--12keV band. Because of radiation damage in orbit, however, the charge-transfer inefficiency (CTI) has increased, and hence the energy…
Super-Hard X-Ray Emission from η Carinae Observed with Suzaku
Hamaguchi, Kenji; Ishida, Manabu; Tsujimoto, Masahiro +4 more
We present the Suzaku results of η Carinae in the 5-50keV range conducted twice around the apastron in 2005 August for 50ks and in 2006 February for 20ks. The X-ray Imaging Spectrometer (XIS) produced hard (5-12keV) band spectra, resolving K shell lines from highly ionized Fe and Ni. The Hard X-ray Detector yielded a significant detection in the s…
Nobeyama Millimeter Array Observations of the Nuclear Starburst of M 83: A GMA Scale Correlation between Dense Gas Fraction and Star Formation Efficiency
Kohno, Kotaro; Kuno, Nario; Nakanishi, Kouichiro +6 more
We present aperture synthesis high-resolution (∼7'' × 3'') observations in CO (J = 1--0), HCN (J = 1--0), and 95GHz continuum emission toward the central (∼1.5 kpc) region of the nearby barred spiral galaxy M 83 with the Nobeyama Millimeter Array. Our high-resolution CO (J = 1--0) mosaic map depicts the presence of molecular ridges along the leadi…
Uniting the Quiescent Emission and Burst Spectra of Magnetar Candidates
Yamaoka, Kazutaka; Nakagawa, Yujin E.; Yoshida, Atsumasa +1 more
Spectral studies of quiescent emission and bursts of magnetar candidates based on XMM-Newton, Chandra, and Swift data are presented. Spectra of both the quiescent emission and the burst for most magnetar candidates are reproduced by a photoelectrically absorbed two-blackbody function (2BB). There is a strong correlation between the lower and highe…
Suzaku Observations of Thermal and Non-Thermal X-Ray Emission from the Middle-Aged Supernova Remnant G156.2+5.7
Katsuda, Satoru; Petre, Robert; Yamaguchi, Hiroya +3 more
We present results from an X-ray analysis of a Galactic middle-aged supernova remnant (SNR), G156.2+5.7, which is bright and largely extended in X-ray wavelengths, showing a clear circular shape (radius ∼50'). Using the Suzaku satellite, we observed this SNR in three pointings: partially covering the northwestern rim, the eastern rim, and the cent…
Timing and Spectral Study of AXJ1745.6-2901 with Suzaku
Maeda, Yoshitomo; Makishima, Kazuo; Koyama, Katsuji +3 more
The eclipsing low-mass X-ray binary AX J1745.6-2901 was observed with Suzaku in its outburst phase. Combining the Chandra observation made 1.5 month earlier than Suzaku, we determined the orbital period to be 30063.76±0.14s. We found deep flux dips prior to the eclipse phase of the orbit. The X-ray spectrum of the persistent phase is described by …
Suzaku Observation of Diffuse X-Ray Emission from the Open Cluster Westerlund 2: a Hypernova Remnant?
Hayashida, Kiyoshi; Fujita, Yutaka; Takahara, Fumio +1 more
We present an analysis of Suzaku observations of the young open cluster Westerlund 2, which is filled with diffuse X-ray emission. We found that the emission consists of three thermal components, or two thermal and one non-thermal components. The upper limit of the energy flux of the non-thermal component is smaller than that in the TeV band obser…
Radial Velocity Search for Extrasolar Planets in Visual Binary Systems
Sato, Bun'ei; Itoh, Yoichi; Oasa, Yumiko +7 more
We searched for extrasolar planets in visual binary systems using precise Doppler-shift measurements taken over a period of 4 yr. Using the HIgh Dispersion Echelle Spectrograph (HIDES) equipped on the Okayama Astrophysical Observatory (OAO) 188cm reflector, we achieved a radial-velocity precision of about 10ms-1. We monitored both prima…
Optically Thick Outflows of Supercritical Accretion Discs: Radiative Diffusion Approach
Karpov, Sergey; Abolmasov, Pavel; Kotani, Taro
Highly supercritical accretion discs are probable sources of dense optically thick axisymmetric winds. We introduce a new approach based on diffusion approximation radiative transfer in a funnel geometry, and obtain an analytical solution for the energy density distribution inside the wind, assuming that all of the mass, momentum and energy are in…
Ejecta Distributions of Heavy Elements in the Cygnus Loop
Katsuda, Satoru; Uchida, Hiroyuki; Tsunemi, Hiroshi +2 more
We analyzed the metal distribution of the Cygnus Loop using 14 and 7 pointing observation data obtained by the Suzaku and XMM-Newton observatories, respectively. The spectral analysis shows that all of the spectra are well fitted by a two-kTe nonequilibrium ionization plasma model, as shown by earlier observations. From the best-fit par…