Search Publications
Calibration and Performance of the AKARI Far-Infrared Surveyor (FIS) -- Slow-Scan Observation Mode for Point-Sources
Nakagawa, Takao; Shirahata, Mai; Hasegawa, Sunao +11 more
We present the characterization and calibration of the Slow-Scan observation mode of the Far-Infrared Surveyor (FIS) onboard the AKARI satellite. The FIS, one of the two focal-plane instruments on AKARI, has four photometric bands between 50--180µm with two types of Ge:Ga array detectors. In addition to the All-Sky Survey, FIS has also taken…
North Ecliptic Pole Wide Field Survey of AKARI: Survey Strategy and Data Characteristics
Kim, Seong Jin; Nakagawa, Takao; Oyabu, Shinki +10 more
We present the survey strategy and the data characteristics of the North Ecliptic Pole (NEP) Wide Survey of AKARI. The survey was carried out for about one year starting from 2006 May with 9 passbands from 2.5 to 24µm and the areal coverage of about 5.8degree² centered on NEP. The survey depth reaches to 21.8 AB magnitude near infrared (NIR)…
Suzaku Observations of SS Cygni in Quiescence and Outburst
Hamaguchi, Kenji; Ishida, Manabu; Hayashi, Takayuki +4 more
We present results from the Suzaku observations of the dwarf nova SS Cyg in quiescence and outburst in 2005 November. The high sensitivity of the HXD PIN and the high spectral resolution of the XIS enabled us to determine the plasma parameters with unprecedented precision. The maximum temperature of the plasma in quiescence, 20.4+4.0
Spatial Distribution of the Galactic Center Diffuse X-Rays and the Spectra of the Brightest 6.4keV Clumps
Koyama, Katsuji; Matsumoto, Hironori; Nobukawa, Masayoshi +4 more
The high energy resolution and low background, particularly in the hard X-ray band, of the X-ray Imaging Spectrometer onboard Suzaku provide excellent spectra of the Galactic center diffuse X-rays (GCDX). This paper reports on the results of spatially resolved spectroscopy of the GCDX. The most pronounced features of the GCDX are the K-shell trans…
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±…