Search Publications
Calibration of the AKARI Far-Infrared Imaging Fourier-Transform Spectrometer
Nakagawa, Takao; Shirahata, Mai; Doi, Yasuo +16 more
The Far-Infrared Surveyor (FIS) onboard the AKARI satellite has a spectroscopic capability provided by a Fourier transform spectrometer (FIS-FTS). FIS-FTS is the first space-borne imaging FTS dedicated to far-infrared astronomical observations. We describe the calibration process of the FIS-FTS, and discuss its accuracy and reliability. The calibr…
Time-Resolved Spectral Variability of the Prompt Emission from GRB 070125 Observed with Suzaku/WAM
Gandhi, Poshak; Yamaoka, Kazutaka; Fukazawa, Yasushi +12 more
Time-resolved spectral analyses of GRB 070125 with significant photon detections over the MeV regime using Suzaku/WAM data are reported. The prompt emission interval was divided into 10 time regions, and their spectra were reproduced by a Band function or a cutoff power-law model. The spectra show a complex evolution; a soft-hard-soft trend is see…
Spectroscopic Studies of Limb Spicules. I Radial and Turbulent Velocities
Shoji, Makiko; Nishikawa, Takara; Kitai, Reizaburo +1 more
We made high-resolution spectroscopic observations of limb spicules in Hα using the Vertical Spectrograph of Domeless Solar Telescope at Hida Observatory. While more than half of the observed spicules have Gaussian line-profiles, some spicules have distinctly asymmetric profiles, which can be fitted to two Gaussian components. The faster component…
A New Candidate of a Cluster of Galaxies, 2XMM J045637.2+522411
Ueno, Masaru; Koyama, Katsuji; Bamba, Aya +1 more
We present XMM-Newton and Suzaku results of an X-ray source, 2XMM J045637.2+522411, found during an observation of a galactic supernova remnant (SNR), G156.2+5.7. By comparing its radial profile with the point-spread function, we found that 2XMM J045637.2+522411 is an extended source. X-ray spectra exhibited a line-like structure at 5.7-5.8 keV. S…
Suzaku Observations of the Supernova Remnant N23 in the Large Magellanic Cloud
Ishida, Manabu; Bamba, Aya; Someya, Kentaro
X-ray emission from the supernova remnant N23 in the Large Magellanic Cloud (LMC) has been studied using the X-ray Imaging Spectrometer (XIS) onboard Suzaku. Thanks to a superior energy resolution of the XIS in the soft X-ray band, we resolved H-like and He-like Oxygen K
On the Relation between Surge Activities and a Photospheric Horizontal Velocity Field
Kitai, Reizaburo
A photospheric horizontal velocity field was observed in an active region, NOAA 8375, which showed high Hα surge activities on 1998 November 6. From analyses of Hα images, the photospheric horizontal velocity field, and the magnetic field in and around the active region, we found the following: (1) Meso-granular or supergranular photospheric horiz…
Modeling and Reproducibility of Suzaku HXD PIN/GSO Background
Isobe, Naoki; Enoto, Teruaki; Yamaoka, Kazutaka +27 more
Suzaku Hard X-ray Detector (HXD) achieved the lowest background level than any other previously or currently operational missions sensitive in the energy range of 10--600keV, by utilizing PIN photodiodes and GSO scintillators mounted in BGO active shields to reject particle background and Compton-scattered events as much as possible. Because it do…
Energy Spectra of the Soft X-Ray Diffuse Emission in Fourteen Fields Observed with Suzaku
Fujimoto, Ryuichi; Yamasaki, Noriko Y.; Wang, Q. Daniel +8 more
The soft diffuse X-ray emission of twelve fields observed with Suzaku are presented together with two additional fields from previous analyses. All have galactic longitudes 65° < l < 295° to avoid contributions from the very bright diffuse source that extends at least 30° from the Galactic center. The surface brightnesses of the Suzaku nine …
Suzaku Observations of Abell 1795: Cluster Emission to r200
Miller, Eric D.; Sanders, Jeremy S.; Hughes, John P. +10 more
We report Suzaku observations of the galaxy cluster Abell 1795 that extend to r_200 ~ 2 Mpc, the radius within which the mean cluster mass density is 200 times the cosmic critical density. These observations are the first to probe the state of the intracluster medium in this object at r > 1.3 Mpc. We sample two disjoint sectors in the cluster o…
New CTI Correction Method for Spaced-Row Charge Injection of the Suzaku X-Ray Imaging Spectrometer
Dotani, Tadayasu; Miller, Eric D.; Mori, Hideyuki +21 more
The charge transfer inefficiency (CTI) of the X-ray CCDs on board the Suzaku satellite (X-ray Imaging Spectrometers; XIS) has increased since the launch due to radiation damage, and the energy resolution has been degraded. To improve the CTI, we have applied a spaced-row charge injection (SCI) technique to the XIS in orbit; by injecting charges in…