Search Publications
X-Ray Halo around the Spiral Galaxy NGC 4631 Observed with Suzaku
Sato, Kosuke; Ohashi, Takaya; Yamasaki, Noriko Y. +1 more
A Suzaku observation of the edge-on spiral galaxy NGC 4631 confirmed its X-ray halo extending out to about 10kpc from the galactic disk. The XIS spectra yielded the temperature and metal abundance for the disk and the halo regions. The observed abundance pattern for O, Ne, Mg, Si, and Fe is consistent with the metal yield from type II supernovae, …
An X-Ray Face-On View of the Sagittarius B Molecular Clouds Observed with Suzaku
Koyama, Katsuji; Nobukawa, Masayoshi; Tsuru, Takeshi Go +2 more
We present a new methodology to derive the positions of the Sagittarius (Sgr) B molecular clouds (MCs) along the line of sight, as an application study of the Galactic center diffuse X-rays (GCDX). The GCDX are composed of hot plasma emission of about 7keV and 1keV temperatures, and non-thermal continuum emission including the 6.4keV line from neu…
The Nature of a Cosmic-Ray Accelerator, CTB37B, Observed with Suzaku and Chandra
Ishida, Manabu; Terada, Yukikatsu; Nakajima, Hiroshi +5 more
We report on Suzaku and Chandra observations of the young supernova remnant CTB37B, from which TeV γ-rays were detected by the H.E.S.S. Cherenkov telescope. The 80ks Suzaku observation provided us with a clear image of diffuse emission and high-quality spectra. The spectra revealed that the diffuse emission is comprised of thermal and non-thermal …
Suzaku Observation of HESS J1825-137: Discovery of Largely-Extended X-Rays from PSR J1826-1334
Koyama, Katsuji; Matsumoto, Hironori; Bamba, Aya +2 more
We observed the brightest part of HESS J1825-137 with the Suzaku XIS, and found diffuse X-rays extending at least up to 15' (∼17pc) from the PSR J1826-1334. The spectra have no emission line, and were fitted with an absorbed power-law model. The X-rays, therefore, are likely to be due to synchrotron emission from a pulsar wind nebula. The photon i…
Iron Emission Lines on the Galactic Ridge Observed with Suzaku
Koyama, Katsuji; Ezoe, Yuichiro; Yamasaki, Noriko Y. +5 more
In order to elucidate the origin of 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 resolved the Fe line complex into three narrow lines at ∼6.4keV, ∼6.7keV and ∼6.97keV, which are K-lines from neutral (or low-ionized), He-like, and H-li…
Suzaku and Multi-Wavelength Observations of OJ 287 during the Periodic Optical Outburst in 2007
Isobe, Naoki; Kohno, Kotaro; Shimajiri, Yoshito +153 more
Suzaku observations of the blazar OJ 287 were performed in 2007 April 10-13 and November 7-9. They correspond to a quiescent and a flaring state, respectively. The X-ray spectra of the source can be well-described with single power-law models in both exposures. The derived X-ray photon index and the flux density at 1 keV were found to be Γ = 1.65±…
Suzaku Observations of M 82 X-1 : Detection of a Curved Hard X-Ray Spectrum
Gandhi, Poshak; Makishima, Kazuo; Miyawaki, Ryohei +5 more
A report is presented on Suzaku observations of the ultra-luminous X-ray source X-1 in the starburst galaxy M 82, made three times in 2005 October for an exposure of ∼30ks each. The XIS signals from a region of radius 3' around the nucleus defined a 2--10keV flux of 2.1 × 10-11erg s-1cm-2 attributable to point sour…
Suzaku Observation of the Radio Halo Cluster Abell 2319: Gas Dynamics and Hard X-Ray Properties
Nakazawa, Kazuhiro; Takizawa, Motokazu; Sugawara, Chika
We present the results of a Suzaku observation of the radio halo cluster Abell 2319 (A 2319). The metal abundance in the central cool region is found to be higher than the surrounding region, which was not resolved in former studies. We confirm that the line-of-sight velocities of the intracluster medium in the observed region are consistent with …
Detection of Hard X-Rays from the Compton-Thick Seyfert 2 Galaxy NGC 2273 with Suzaku
Fukazawa, Yasushi; Awaki, Hisamitsu; Terashima, Yuichi +1 more
We have obtained a broad-band spectrum of the Compton-thick Seyfert 2 galaxy NGC 2273 with Suzaku. The spectrum reveals the first detection of hard X-rays above ∼10keV from NGC 2273. The broad-band spectrum is well represented by a three component model, accompanied by both a strong iron Kα line with an equivalent width of ∼1.8keV and several weak…
Suzaku Observation of Group of Galaxies NGC 507: Temperature and Metal Distributions in the Intra-Cluster Medium
Ishida, Manabu; Sato, Kosuke; Ohashi, Takaya +3 more
The temperature and abundance distributions of the intra-cluster medium (ICM) in the NGC 507 group of galaxies were studied with Suzaku. The observed concentric annular spectra were well-represented by a two-temperature model for ICM, and steeper abundance gradients were found for Mg, Si, S, and Fe compared with O in the central region. The abunda…