Search Publications
Systematic X-Ray Analysis of Radio Relic Clusters with Suzaku
Akamatsu, Hiroki; Kawahara, Hajime
We undertook a systematic X-ray analysis of six giant radio relics in four clusters of galaxies using the Suzaku satellite. The sample included CIZA 2242.8+5301, Zwcl 2341.1-0000, the South-East part of A 3667 and previously published results of the North-West part of A 3667 and A 3376. Especially, we first observed the narrow (50 kpc) relic of CI…
K-Shell Line Distribution of Heavy Elements along the Galactic Plane Observed with Suzaku
Koyama, Katsuji; Nobukawa, Masayoshi; Tsuru, Takeshi Go +1 more
We report on the global distribution of the intensities of the K-shell lines from He-like and H-like ions of S, Ar, Ca, and Fe along the Galactic plane. From the profiles, we clearly separate the Galactic center X-ray emission (GCXE) and the Galactic ridge X-ray emission (GRXE). The intensity profiles of the He-like Kα lines of S, Ar, Ca, and Fe a…
X-Ray Echo from the Sagittarius C Complex and 500-year Activity History of Sagittarius A*
Koyama, Katsuji; Nobukawa, Masayoshi; Nakashima, Shinya +3 more
This paper presents Suzaku results obtained for the Sagittarius (Sgr) C region using the concept of X-ray reflection nebulae (XRNe) as the echo of past flares from a super-massive black hole, Sgr A*. The Sgr C complex is composed of several molecular clouds proximately located in projected distance. The X-ray spectra of Sgr C were analyzed based o…
Evidence for a Cool Disk and Inhomogeneous Coronae from Wide-Band Temporal Spectroscopy of Cygnus X-1 with Suzaku
Done, Chris; Makishima, Kazuo; Yamada, Shin'ya +3 more
Unified X-ray spectral and timing studies of Cygnus X-1 in the low/hard and hard intermediate state were conducted in a model-independent manner, using broadband Suzaku data acquired on 25 occasions from 2005 to 2009 with a total exposure of ∼ 450 ks. The unabsorbed 0.1-500 keV source luminosity changed over 0.8%-2.8% of the Eddington limit for 14…
The Nature of Stable Soft X-Ray Emissions in Several Types of Active Galactic Nuclei Observed by Suzaku
Makishima, Kazuo; Nakazawa, Kazuhiro; Yamada, Shin'ya +3 more
To constrain the origin of the soft X-ray excess phenomenon seen in many active galactic nuclei, the intensity-correlated spectral analysis, developed by Noda et al. (2011, PASJ, 63, S925) for Markarian 509, was applied to wide-band (0.5-45 keV) Suzaku data of five representative objects with a relatively weak reflection signature. They are the ty…
Suzaku X-Ray Observations of the Accreting NGC 4839 Group of Galaxies and a Radio Relic in the Coma Cluster
Sarazin, Craig L.; Inoue, Susumu; Akamatsu, Hiroki +3 more
Based on Suzaku X-ray observations, we studied the hot gas around the NGC 4839 group of galaxies and a radio relic in the outskirts of the Coma cluster. We found a gradual decline in the gas temperature from 5 keV around NGC 4839 to 3.6 keV at the radio relic, across which there is a further, steeper drop down to 1.5 keV. This drop as well as the …
Evidence for Recombining Plasma in the Supernova Remnant G346.6-0.2
Koyama, Katsuji; Nobukawa, Masayoshi; Yamauchi, Shigeo +1 more
We present Suzaku results of the supernova remnant (SNR) G346.6-0.2. The X-ray emission has a center-filled morphology with a size of 67' × 8' within the radio shell. Neither an ionization equilibrium nor non-equilibrium (ionizing) plasma can reproduce the spectra remaining shoulder-like residuals in the 2-4 keV band. These structures are possibly…
Suzaku Observation of Strong Solar-Wind Charge-Exchange Emission from the Terrestrial Exosphere during a Geomagnetic Storm
Miyoshi, Yoshizumi; Ezoe, Yuichiro; Ishikawa, Kumi +3 more
We present an analysis of X-ray data exhibiting strong solar-wind charge-exchange emission obtained with the Suzaku satellite during a geomagnetic storm that occurred on 2005 August 31. A temporal variation of diffuse soft X-ray emission, correlating with the solar-wind proton flux, was found. The diffuse emission consisted of exospheric solar-win…
X-Ray and Optical Monitoring of a Gamma-Ray-Emitting Radio Galaxy, NGC 1275
Fukazawa, Yasushi; Yamazaki, Syoko; Sasada, Mahito +7 more
We performed monitoring observations of a gamma-ray-emitting radio galaxy, NGC 1275, in the X-ray and optical bands with the Suzaku/XIS, Kanata telescope, and the Okayama telescope. The X-ray flux of the nucleus was estimated by imaging spectroscopy in the hard X-ray band. In the optical band, a continuum flux, a broad Hα line flux, and the polari…
X-Ray Observations of the W 51 Complex with Suzaku
Fukazawa, Yasushi; Hanabata, Yoshitaka; Bamba, Aya +2 more
We present a detailed analysis of X-ray emission from the middle-aged supernova remnant W 51 C and star-forming region W 51 B with Suzaku. The soft X-ray emission from W 51 C is well-represented by an optically thin thermal plasma in a non-equilibrium ionization state with a temperature of