Search Publications
Suzaku Investigation into the Nature of the Nearest Ultraluminous X-Ray Source, M33 X-8
Isobe, Naoki; Kubota, Aya; Mizuno, Tsunefumi +1 more
The X-ray spectrum of the nearest ultraluminous X-ray source, M 33 X-8, obtained by Suzaku during 2010 January 11-13, was closely analyzed in order to examine its nature. It is, by far, the only data with the highest signal statistic in the 0.4-10 keV range. Despite being able to reproduce the X-ray spectrum, Comptonization of the disk photons fai…
Suzaku Observation of Nearby On-Going Merger Cluster Abell 3627
Fukazawa, Yasushi; Nishino, Sho; Hayashi, Katsuhiro
We present the results of the Suzaku observation of a nearby (z = 0.016), on-going merger cluster, Abell 3627. The overall temperature of the ICM is around 7 keV, and we found a cool region with kT ∼ 4-5 keV at the position corresponding to the brightness excess from a spherically symmetrical β-model found by ROSAT. This structure seems to be a su…
Slow-Scan Observations with the Infrared Camera (IRC) aboard AKARI
Oyabu, Shinki; Yamamura, Issei; Takita, Satoshi +6 more
We present the characterization and calibration of the slow-scan observation mode of the Infrared Camera (IRC) aboard AKARI. The IRC Slow-scan observations were operated at the S9W (9µm) and L18W (18µm) bands. We developed a toolkit for data reduction of the IRC Slow-scan observations. We introduced a "self-pointing reconstruction" met…
Suzaku X-Ray Observation of the Dwarf Nova Z Camelopardalis at the Onset of an Optical Outburst
Ishida, Manabu; Tsujimoto, Masahiro; Ebisawa, Ken +1 more
We present the result of a Suzaku X-ray spectroscopic observation of the dwarf nova Z Cam, which was conducted by chance at the onset of an optical outburst. We used the X-ray Imaging Spectrometer (a 38 ks exposure) and the Hard X-ray Detector (34 ks) to obtain a 0.35-40 keV spectrum simultaneously. Spectral characteristics suggest that the source…
Distance and Reddening of the Isolated Dwarf Irregular Galaxy NGC 1156
Kim, Minjin; Lee, Joon Hyeop; Kyeong, Jaemann +3 more
We present a photometric estimation of the distance and reddening values to the dwarf irregular galaxy NGC 1156, that is one of the best targets for the study of isolated dwarf galaxies in the nearby universe. We used imaging data sets of the Hubble Space Telescope (HST) Advanced Camera for Surveys, High Resolution Channel of the central region of…
Spatial and Temporal Variations of the Diffuse Iron 6.4 keV Line in the Galactic Center Region
Koyama, Katsuji; Matsumoto, Hironori; Nobukawa, Masayoshi +4 more
We analyzed the diffuse Fe I Kα line generated in the diffuse interstellar molecular hydrogen by primary photons or subrelativistic protons injected by Sagittarius (Sgr) A*. We showed that unlike emission from compact molecular clouds, this emission can be permanently observed in the directions of the Galactic center. We conclude that the diffuse …
Suzaku Observations of Unidentified X-Ray Sources toward the Galactic Bulge
Dotani, Tadayasu; Maeda, Yoshitomo; Ishida, Manabu +2 more
We present Suzaku observations of two unidentified sources towards the Galactic bulge, 1RXS J165256.3
Spectral Evolutions in Gamma-Ray Burst Exponential Decays Observed with Suzaku WAM
Yamaoka, Kazutaka; Onda, Kaori; Sugita, Satoshi +4 more
This paper presents a study on the spectral evolution of gamma-ray burst (GRB) prompt emissions observed with the Suzaku Wide-band All-sky Monitor (WAM). By making use of the WAM data archive, 6 bright GRBs exhibiting 7 well-separated fast-rise-exponential-decay (FRED) shaped light curves are presented, and the evaluated exponential decay time con…
Self-Charge-Filling (SCF) Effect of Suzaku XIS
Kitamoto, Shunji; Murakami, Hiroshi; Yoshida, Yuki +1 more
We demonstrate the importance of the self-charge-filling (SCF) effect for the analysis of bright and line-rich sources with the Suzaku X-ray imaging spectrometer (XIS) if spaced-row charge injection (SCI) is not applied. The SCF-effect changes the central energy of lines depending on the extracted region or the event densities of the images. We pr…
Suzaku Observations of Abell 1555 and Abell 1558: Searching for Non-Thermal Emission from Large-Scale Structure Formation
Nakazawa, Kazuhiro; Makiya, Ryu; Totani, Tomonori
We report on X-ray observations of two galaxy clusters, Abell 1555 and Abell 1558, with Suzaku, which are included in a large-scale filamentary structure and a supercluster, to search for non-thermal emission driven by shocks produced during structure formation. These two clusters were detected by Suzaku/XIS for the first time in the X-ray band of…