Search Publications
Reproducibility of Non-X-Ray Background for the X-Ray Imaging Spectrometer aboard Suzaku
Dotani, Tadayasu; Miller, Eric D.; Yamaguchi, Hiroya +9 more
One of the advantages of the X-ray Imaging Spectrometer (XIS) system aboard Suzaku is its low and stable non-X-ray background (NXB). In order to make the best use of this advantage, modeling the NXB spectra with high accuracy is important to subtract them from the spectra of on-source observations. We are constructing an NXB database by collecting…
Subaru Weak Lensing Study of Seven Merging Clusters: Distributions of Mass and Baryons
Umetsu, Keiichi; Okabe, Nobuhiro
We present and compare projected distributions of mass, galaxies, and the intracluster medium (ICM) for a sample of merging clusters of galaxies based on a joint weak-lensing, optical photometric, and X-ray analysis. Our sample comprised seven nearby Abell clusters, for which we had conducted systematic, deep imaging observations with Suprime-Cam …
High Metallicity of the X-Ray Gas Up to the Virial Radius of a Binary Cluster of Galaxies: Evidence of Galactic Superwinds at High-Redshift
Reiprich, Thomas H.; Hayashida, Kiyoshi; Matsumoto, Hironori +4 more
We present an analysis of a Suzaku observation of the link region between the galaxy clusters A 399 and A 401. We obtained the metallicity of the intracluster medium (ICM) up to the cluster virial radii for the first time. We determined the metallicity where the virial radii of the two clusters cross each other (∼2 Mpc away from their centers) and…
Suzaku Results on Cygnus X-1 in the Low/Hard State
Done, Chris; Dotani, Tadayasu; Yamaoka, Kazutaka +9 more
The black-hole binary Cygnus X-1 was observed for 17ks with the Suzaku X-ray observatory in 2005 October, while it was in a low/hard state with a 0.7-300keV luminosity of 4.6×1037ergs-1. The XIS and HXD spectra, spanning 0.7--400keV, were reproduced successfully, incorporating a cool accretion disk and a hot Comptonizing coro…
Systematic Infrared 2.5-5 µm Spectroscopy of Nearby Ultraluminous Infrared Galaxies with AKARI
Nakagawa, Takao; Shirahata, Mai; Imanishi, Masatoshi +4 more
We report on the results of systematic infrared 2.5-5 µm spectroscopy of 45 nearby ultraluminous infrared galaxies (ULIRGs) at z < 0.3 using AKARI IRC. This paper investigates whether the luminosities of these ULIRGs are dominated by starburst activity, or alternatively, whether optically elusive buried active galactic nuclei (AGNs) are e…
AKARI/IRC Deep Survey in the North Ecliptic Pole Region
Goto, Tomotsugu; Oyabu, Shinki; Ohyama, Youichi +10 more
We have made adeep and wide imaging survey with all nine AKARI/IRC bands from 2 to 24 µm within ahalf degree of the North Ecliptic Pole. The survey covered acircular area of 0.38deg2 centered at RA = 17h56m, Dec = 66°37' where adeep optical multi-band survey has been conducted by Subaru/Suprime-Cam. The 5σ se…
Restoring the Suzaku Source Position Accuracy and Point-Spread Function
Maeda, Yoshitomo; Ishida, Manabu; Iizuka, Ryo +9 more
We present an empirical correction of sky coordinates of X-ray photons obtained with the X-ray Imaging Spectrometer (XIS) aboard the Suzaku satellite to improve the source position accuracy and restore the point-spread function (PSF). The XIS images are known to have an uncertainty in position of up to 1', and to show considerable degradations of …
Performance of the Charge-Injection Capability of Suzaku XIS
Dotani, Tadayasu; Katsuda, Satoru; Yamaguchi, Hiroya +17 more
A charge-injection technique is applied to the X-ray CCD camera, XIS (X-ray Imaging Spectrometer) aboard Suzaku. The charge transfer inefficiency (CTI) in each CCD column (vertical transfer channel) is measured by the injection of charge packets into a transfer channel and subsequent readout. This paper reports on the performances of the charge-in…
Suzaku Discovery of Hard X-Ray Pulsations from a Rotating Magnetized White Dwarf, AEAquarii
Dotani, Tadayasu; Ishida, Manabu; Hayashi, Takayuki +7 more
A fast rotating magnetized white dwarf, AEAquarii, was observed with Suzaku, in 2005 October-November and 2006 October with exposures of 53.1 and 42.4ks, respectively. In addition to clear spin modulation in the 0.5-10keV band of the XIS data at the barycentric period of 33.0769±0.0001s, the 10-30keV HXD data in the second half of the 2005 observa…
X-Ray Spectroscopy of SN 1006 with Suzaku
Katsuda, Satoru; Yamaguchi, Hiroya; Koyama, Katsuji +7 more
We report on observations of SN 1006 with Suzaku. We firmly detected K-shell emission from Fe, for the first time, and found that the Fe ionization state is quite low. The broad-band spectrum extracted from southeast of the remnant was well-fitted with a model consisting of three optically thin thermal non-equilibrium ionization plasmas and a powe…