Search Publications
An X-ray spectroscopic search for dark matter in the Perseus cluster with Suzaku
Maeda, Yoshitomo; Iizuka, Ryo; Mitsuda, Kazuhisa +2 more
We present the results from deep Suzaku observations of the central region of the Perseus cluster. Bulbul et al. (2014, ApJ, 789, 13) reported the detection by XMM-Newton instruments of an unidentified X-ray emission line at an energy around 3.5 keV in spectra for the Perseus and other clusters. They argued for a possibility of the decay of steril…
Suzaku observations of the galaxy cluster 1RXS J0603.3+4214: Implications of particle acceleration processes in the "Toothbrush" radio relic
Ohashi, Takaya; Takizawa, Motokazu; Akamatsu, Hiroki +4 more
We present the results of Suzaku observations of the galaxy cluster 1RXS J0603.3+4214 with the "Toothbrush" radio relic. Although a shock with Mach number M ≃ 4 is expected at the outer edge of the relic from the radio observation, our temperature measurements of the intracluster medium indicate a weaker temperature difference than expected. The M…
Suzaku monitoring of the Wolf-Rayet binary WR 140 around periastron passage: An approach for quantifying the wind parameters
Hamaguchi, Kenji; Sugawara, Yasuharu; Maeda, Yoshitomo +7 more
Suzaku observations of the Wolf-Rayet (W-R) binary WR 140 (WC7pd+O5.5fc) were made at four different times around periastron passage in 2009 January. The spectra changed in shape and flux with the phase. As periastron approached, the column density of the low-energy absorption increased, which indicates that the emission from the wind-wind collisi…
Suzaku studies of the supernova remnant CTB 109 hosting the magnetar 1E 2259+586
Enoto, Teruaki; Makishima, Kazuo; Kaneda, Hidehiro +4 more
Ages of the magnetar 1E 2259+586 and the associated supernova remnant CTB 109 were studied. Analyzing the Suzaku data of CTB 109, its age was estimated to be ∼ 14 kyr, which is much younger than the measured characteristic age of 1E 2259+586, 230 kyr. This reconfirms the previously reported age discrepancy of this magnetar/remnant association, and…
Radio relics tracing the projected mass distribution in CIZA J2242.8+5301*
Umetsu, Keiichi; Fujita, Yutaka; Okabe, Nobuhiro +4 more
We present a weak-lensing analysis for a merging galaxy cluster, CIZA J2242.8+5301, which hosts double radio relics, using three-band Subaru/Suprime-Cam imaging (Br'z'). Since the lifetime of dark matter halos colliding into clusters is longer than that of X-ray emitting gas halos, weak-lensing analysis is a powerful method t…
Global distribution of ionizing and recombining plasmas in the supernova remnant G290.1-0.8
Katsuda, Satoru; Koyama, Katsuji; Uchida, Hiroyuki +5 more
We report on the Suzaku results of the mixed-morphology supernova remnant (SNR) G290.1-0.8 (MSH 11-61A). The SNR has an asymmetric structure extended to the south-east and the north-west. In the X-ray spectra of the center and the north-west regions, we discover recombining plasma features with a strong Si Lyα and radiative recombination continuum…
Discovery of a nearby early-phase major cluster merger CIZA J1358.9-4750
Makishima, Kazuo; Nakazawa, Kazuhiro; Gu, Liyi +4 more
CIZA J1358.9-4750 is a nearby (z = 0.074) pair of clusters of galaxies located close to the Galactic plane. It consists of two X-ray extended humps at the northwest and the southeast separated by 14' (∼ 1.2 Mpc), and an X-ray bright bridgelike structure in between. With Suzaku, the south east hump was shown to have a temperature of 5.6 ± 0.2 keV a…
X-ray measurement of electron and magnetic-field energy densities in the west lobe of the giant radio galaxy 3C 236
Isobe, Naoki; Koyama, Shoko
X-ray emission associated with the west lobe of the giant radio galaxy 3C 236 was investigated with the Suzaku observatory to evaluate the energetics in the lobe. After removing contamination from point-like X-ray sources detected with Chandra and subtracting the X-ray and non-X-ray backgrounds, the Suzaku spectrum from the lobe was reproduced by …
Sub-MeV band observation of a hard burst from AXP 1E 1547.0-5408 with the Suzaku Wide-band All-sky Monitor
Enoto, Teruaki; Yamaoka, Kazutaka; Makishima, Kazuo +10 more
The 2.1-s anomalous X-ray pulsar 1E 1547.0-5408 exhibited an X-ray outburst on 2009 January 22, emitting a large number of short bursts. The wide-band all-sky monitor (WAM) on-board Suzaku detected at least 254 bursts in the 160 keV-6.2 MeV band over the period of January 22 00:57-17:02 UT from the direction of 1E 1547.0-5408. One of these bursts,…
Suzaku observation of X-ray variability in soft state LMC X-1
Makishima, Kazuo; Tashiro, Makoto S.; Terada, Yukikatsu +3 more
This paper reports the results of Suzaku observation of the spectral variation of the black hole binary LMC X-1 in the soft state. The observation was carried out in 2009 from July 21 to 24. the obtained net count rate was ∼ 30 counts s-1 in the 0.5-50 keV band with ∼ 10% peak-to-peak flux variation. The time-averaged X-ray spectrum can…