Search Publications
Suzaku Wide-band All-sky Monitor measurements of duration distributions of gamma-ray bursts
Yamaoka, Kazutaka; Fukazawa, Yasushi; Hanabata, Yoshitaka +25 more
We report on the T90 and T50 duration distributions and their relations with spectral hardness using 1464 gamma-ray bursts (GRBs), which were observed by the Suzaku Wide-band All-sky Monitor (WAM) from 2005 August 4 to 2010 December 29. The duration distribution is clearly bimodal in three energy ranges (50-120, 120-250, and …
Suzaku follow-up of heavily obscured active galactic nuclei detected in Swift/BAT survey: NGC 1106, UGC 03752, and NGC 2788A
Tanimoto, Atsushi; Ueda, Yoshihiro; Kawamuro, Taiki +1 more
We present the broad-band (0.5-100 keV) spectra of three heavily obscured active galactic nuclei (AGNs), NGC 1106, UGC 03752, and NGC 2788A, observed with Suzaku and the Swift/Burst Alert Telescope (BAT). The targets are selected from the Swift/BAT 70-month catalog on the basis of their high hardness ratio between above and below 10 keV, and their…
Suzaku observations of the hard X-ray spectrum of Vela Jr. (SNR RX J0852.0-4622)
Katsuda, Satoru; Tashiro, Makoto S.; Terada, Yukikatsu +5 more
We report the results of Suzaku observations of the young supernova remnant, Vela Jr. (RX J0852.0-4622), which is known to emit synchrotron X-rays, as well as TeV gamma-rays. Utilizing 39 Suzaku mapping observation data from Vela Jr., a significant hard X-ray emission is detected with the hard X-ray detector (HXD) from the northwest TeV-emitting r…
Revised calibration for near- and mid-infrared images from ∼4000 pointed observations with AKARI/IRC
Onaka, Takashi; Yamamura, Issei; Usui, Fumihiko +3 more
The Japanese infrared astronomical satellite AKARI performed ∼4000 pointed observations for 16 months until the end of August 2007, when the telescope and instruments were cooled by liquid helium. Observation targets include solar system objects, Galactic objects, local galaxies, and galaxies at cosmological distances. We describe recent updates o…
Chemical evolution of the HC3N and N2H+ molecules in dense cores of the Vela C giant molecular cloud complex
Sanhueza, Patricio; Choi, Minho; Tatematsu, Ken'ichi +5 more
We have observed the HC3N(J = 10-9) and N2H+ (J = 1-0) lines toward the Vela C molecular clouds with the Mopra 22 m telescope to study the chemical characteristics of dense cores. The intensity distributions of these molecules are similar to each other at an angular resolution of 53″, corresponding to 0.19 pc, sugg…
X-ray observations of a subhalo associated with the NGC 4839 group infalling toward the Coma cluster
Sato, Kosuke; Okabe, Nobuhiro; Matsushita, Kyoko +1 more
We report on Suzaku X-ray observations of the dark subhalo associated with the merging group of NGC 4839 in the Coma cluster. The X-ray image exhibits an elongated tail toward the southwest. The X-ray peak shifts approximately 1' away from the weak-lensing mass center toward the opposite direction of the Coma cluster center. We investigated the te…
AKARI far-infrared maps of the zodiacal dust bands
Nakagawa, Takao; Doi, Yasuo; Takita, Satoshi +6 more
Zodiacal emission is thermal emission from interplanetary dust. Its contribution to the sky brightness is non-negligible in the region near the ecliptic plane, even in the far-infrared (far-IR) wavelength regime. We analyze zodiacal emission observed by the AKARI far-IR all-sky survey, which covers 97% of the entire sky at arcminute-scale resoluti…
Peculiar lapse of periodic eclipsing event at low-mass X-ray binary GRS 1747-312 during Suzaku observation in 2009
Dotani, Tadayasu; Maeda, Yoshitomo; Mori, Hideyuki +6 more
GRS 1747-312 is a neutron star low-mass X-ray binary in the globular cluster Terzan 6, located at a distance of 9.5 kpc from the Earth. During its outbursts, periodic eclipses were known to occur. Observations for the outbursts were performed with Chandra in 2004 and Swift in 2013. XMM-Newton observed its quiescent state in 2004. In addition, when…
A Suzaku observation of the low-mass X-ray binary GS 1826-238 in the hard state
Makishima, Kazuo; Nakazawa, Kazuhiro; Zhang, Zhongli +2 more
The neutron star low-mass X-ray binary GS 1826-238 was observed with Suzaku on 2009 October 21, for a total exposure of 1030 ks. Except for the type I bursts, the source intensity was constant within ∼10%. Combining the Suzaku XIS, HXD-PIN, and HXD-GSO data, burst-removed persistent emission was detected over the 0.8-100 keV range, at an unabsorbe…
A systematic study of evolved supernova remnants in the large and small Magellanic Clouds with Suzaku
Yamaguchi, Hiroya; Tamagawa, Toru; Takeuchi, Yoko
Identifying the origin type (i.e., Type Ia or core-collapse) of supernova remnants (SNRs) is crucial to determining the rates of supernova (SN) explosions in a galaxy, which is a key to understanding its recent chemical evolution. However, evolved SNRs in the so-called Sedov phase are dominated by the swept-up interstellar medium (ISM), making it …