Search Publications
Search for gas bulk motions in eight nearby clusters of galaxies with Suzaku
Ota, Naomi; Yoshida, Hiroko
To search for bulk motions of the intracluster medium, we analyzed X-ray spectra taken with the Suzaku satellite, and measured the Doppler shift of the Fe-K line emission from eight nearby clusters of galaxies with various X-ray morphologies. In the cores of the Centaurus and Perseus clusters, the gas bulk velocity does not exceed the sound veloci…
Origin of the characteristic X-ray spectral variations of IRAS 13224-3809
Ebisawa, Ken; Mizumoto, Misaki; Sameshima, Hiroaki +1 more
The narrow-line Seyfert 1 galaxy (NLS1) IRAS 13224-3809 is known to exhibit significant X-ray spectral variation, a sharp spectral drop at ∼7 keV, strong soft excess emission, and a hint of an iron L-edge feature, which is very similar to the NLS1 1H 0707-495. We have proposed the "Variable Double Partial Covering (VDPC) model" to explain the ener…
X-ray observations of a subhalo associated with the NGC 4839 group infalling toward the Coma cluster
Sato, Kosuke; Okabe, Nobuhiro; Matsushita, Kyoko +1 more
We report on Suzaku X-ray observations of the dark subhalo associated with the merging group of NGC 4839 in the Coma cluster. The X-ray image exhibits an elongated tail toward the southwest. The X-ray peak shifts approximately 1' away from the weak-lensing mass center toward the opposite direction of the Coma cluster center. We investigated the te…
Peculiar lapse of periodic eclipsing event at low-mass X-ray binary GRS 1747-312 during Suzaku observation in 2009
Dotani, Tadayasu; Maeda, Yoshitomo; Mori, Hideyuki +6 more
GRS 1747-312 is a neutron star low-mass X-ray binary in the globular cluster Terzan 6, located at a distance of 9.5 kpc from the Earth. During its outbursts, periodic eclipses were known to occur. Observations for the outbursts were performed with Chandra in 2004 and Swift in 2013. XMM-Newton observed its quiescent state in 2004. In addition, when…
A systematic study of evolved supernova remnants in the large and small Magellanic Clouds with Suzaku
Yamaguchi, Hiroya; Tamagawa, Toru; Takeuchi, Yoko
Identifying the origin type (i.e., Type Ia or core-collapse) of supernova remnants (SNRs) is crucial to determining the rates of supernova (SN) explosions in a galaxy, which is a key to understanding its recent chemical evolution. However, evolved SNRs in the so-called Sedov phase are dominated by the swept-up interstellar medium (ISM), making it …
Suzaku observation of a high-entropy cluster Abell 548W
Makishima, Kazuo; Nakazawa, Kazuhiro; Gu, Liyi +4 more
Abell 548W, one of the galaxy clusters located in the Abell 548 region, has about an order of magnitude lower X-ray luminosity compared to ordinal clusters in view of the well-known intracluster medium (ICM) temperature vs. X-ray luminosity (kT-LX) relation. The cluster hosts a pair of diffuse radio sources to the northwest and north, b…
Suzaku observations of two diffuse hard X-ray source regions, G22.0+0.0 and G23.5+0.1
Bamba, Aya; Yamauchi, Shigeo; Sumita, Mayu
G22.0+0.0 and G23.5+0.1 are diffuse hard X-ray sources discovered in the ASCA Galactic Plane Survey. We present Suzaku results of spectral analysis for these sources. G22.0+0.0 is confirmed to be a largely extended emission. Its spectra were represented by a highly absorbed power-law model with a photon index of 1.7 ± 0.3 and a moderately absorbed…
XMM-Newton and Suzaku spectroscopic studies of unidentified X-ray sources towards the Galactic bulge: 1RXS J180556.1-343818 and 1RXS J173905.2-392615
Maeda, Yoshitomo; Mori, Hideyuki; Ueda, Yoshihiro
With XMM-Newton and Suzaku observations, for the first time, we acquired broad-band spectra of two unidentified X-ray sources towards the Galactic bulge: 1RXS J180556.1-343818 and 1RXS J173905.2-392615. The 1RXS J180556.1-343818 spectrum in the 0.3-7 keV band was explained by X-ray emission that originated from an optically-thin thermal plasma wit…