Search Publications

Time Variability of the Neutral Iron Lines from the Sagittarius B2 Region and Its Implication of a Past Outburst of Sagittarius A

Koyama, Katsuji; Matsumoto, Hironori; Tsuru, Takeshi Go +1 more

We investigated long-term X-ray behavior from the Sgr B2 complex using archival data of the X-ray satellites Suzaku, XMM-Newton, Chandra, and ASCA. The observed region of the Sgr B2 complex included two prominent spots in the FeI Kα line at 6.40keV, a giant molecular cloud, M0.66-0.02, known as the ``Sgr B2 cloud'' and an unusual X-ray source, G0.…

Hard X-Ray Properties of the Merging Cluster Abell 3667 as Observed with Suzaku

Sarazin, Craig L.; Fukazawa, Yasushi; Makishima, Kazuo +10 more

Wide-band Suzaku data on the merging cluster Abell 3667 were examined for hard X-ray emission in excess to the known thermal component. Suzaku detected X-ray signals in a wide energy band from 0.5 to 40keV. The hard X-ray (>10keV) flux observed by the HXD around the cluster center cannot be explained by a simple extension of the thermal emissio…

The Nature of Unresolved Soft X-Ray Emission from the Galactic Disk

Mitsuda, Kazuhisa; Yamasaki, Noriko Y.; McCammon, Dan +4 more

Although about 40% of the soft X-ray background emission in 0.4 to 1keV range has extragalactic origins and thus is totally blocked by the galactic absorption in midplane directions, it decreases at most by about 20% in midplane. Suzaku observation of the direction, (l, b) = (235°, 0°), showed an OVII Kα emission intensity comparable with that of …

Suzaku Observations of Tycho's Supernova Remnant

Kunieda, Hideyo; Szymkowiak, Andrew; Kokubun, Motohide +19 more

Tycho's supernova remnant was observed by the XIS and HXD instruments onboard the Suzaku satellite on 2006 June 26--29 for 92ks. The spectrum up to 30keV was well fitted with a two-component model, consisting of a power-law with a photon index of 2.7 and a thermal bremsstrahlung model with a temperature of 4.7keV. The former component can alternat…

Design and In-Orbit Performance of the Suzaku Wide-Band All-Sky Monitor

Enoto, Teruaki; Yamaoka, Kazutaka; Endo, Akira +38 more

Suzaku X-Ray Imaging and Spectroscopy of Cassiopeia A

Maeda, Yoshitomo; Ishida, Manabu; Petre, Robert +26 more

Suzaku X-ray observations of a young supernova remnant, Cassiopeia A, were carried out. K-shell transition lines from highly ionized ions of various elements were detected, including Chromium (Cr-Kα at 5.61 keV). The X-ray continuum spectra were modeled in the 3.4-40 keV band, summed over the entire remnant, and were fitted with a simplest combina…

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…