Search Publications
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…
Indications of M-dwarf deficits in the halo and thick disk of the Galaxy
Henning, Thomas; Terada, Hiroshi; Usuda, Tomonori +55 more
We compared the number of faint stars detected in deep survey fields with the current stellar distribution model of the Galaxy and found that the detected number in the H band is significantly smaller than the predicted number. This indicates that M-dwarfs, the major component, are fewer in the halo and the thick disk. We used archived data of sev…
Interaction between an emerging flux region and a pre-existing fan-spine dome observed by IRIS and SDO
Yang, Shuhong; Zhang, Jun; Jiang, Fayu
We present multiwavelength observations of a fan-spine dome in the active region NOAA 11996 with the Interface Region Imaging Spectrograph (IRIS) and the Atmospheric Imaging Assembly on board the Solar Dynamics Observatory (SDO) on 2014 March 9. The destruction of the fan-spine topology owing to the interaction between its magnetic fields and a ne…
Witness of gas infall and outflow in the young starburst dwarf galaxy NGC 5253
Hirota, Akihiko; Nakanishi, Kouichiro; Espada, Daniel +2 more
We present 12CO(2-1) observations towards the dwarf galaxy NGC 5253 using the Submillimeter Array. The data shows that a large amount of molecular gas is located in the central ∼ 200 pc starburst region, physically associated with two young super stellar clusters (SSCs). The molecular gas traced by 12CO(2-1) is elongated alon…
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 …
A statistical analysis of current helicity and twist in solar active regions over the phases of the solar cycle using the spectro-polarimeter data of Hinode
Sakurai, Takashi; Otsuji, Kenichi; Kuzanyan, Kirill
Current helicity and twist of solar magnetic fields are important in characterizing the dynamo mechanism working in the convection zone of the Sun. We have carried out a statistical study on the current helicity of solar active regions observed with the spectro-polarimeter (SP) of the Hinode Solar Optical Telescope (SOT). We used SOT-SP data of 55…
Coupling of the magnetic field and gas flows inferred from the net circular polarization in a sunspot penumbra
Ichimoto, Kiyoshi; Shaltout, Abdelrazek M. K.
We analyze penumbral fine structure using high-resolution spectropolarimetric data obtained by the Solar Optical Telescope on board the Hinode satellite. The spatial correlation between the net circular polarization (NCP) and Evershed flow is investigated in detail. Here we obtain that negative NCP structures are correlated with the Evershed flow …
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,…