著者

Tamagawa Toru Hayato Asami Nakamura Satoshi TERADA Yukikatsu BAMBA Aya HIRAGA Junko S. HUGHES John P. HWANG Una KATAOKA Jun KINUGASA Kenzo KUNIEDA Hideyo TANAKA Takaaki TSUNEMI Hiroshi UENO Masaru HOLT Stephen S. KOKUBUN Motohide MIYATA Emi SZYMKOWIAK Andrew TAKAHASHI Tadayuki TAMURA Keisuke UENO Daisuke MAKISHIMA Kazuo

出版者

社団法人日本天文学会

雑誌

PASJ : publications of the Astronomical Society of Japan (ISSN:00046264)

巻号頁・発行日

vol.61, no.1, pp.S167-S174, 2009-01-30

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Tycho's supernova remnant was observed by the XIS and HXD instruments onboard the Suzaku satellite on 2006 June 26-29 for 92 ks. The spectrum up to 30 keV was well fitted with a two-component model, consisting of a power-law with photon index of 2.7 and a thermal bremsstrahlung model with temperature of 4.7 keV. The former component can alternatively be modeled as synchrotron emission from a population of relativistic electrons with an estimated roll-off energy of around 1 keV. In the XIS spectra, in addition to the prominent Fe K_alpha line (6.445 keV), we observe for the first time significant K_alpha line emission from the trace species Cr and Mn at energies of 5.48 keV and 5.95 keV, respectively. Faint K_beta lines from Ca (4.56 keV) and Fe (7.11 keV) are also seen. The ionization states of Cr and Mn, based on their line centroids, are estimated to be similar to that of Fe K_alpha (Fe XV or XVI).

著者

谷津 陽一 片岡 淳 五十川 知子 河合 誠之 水野 恒史 釜江 常好 田島 宏康 高橋 忠幸 斉藤 芳隆 郡司 修一 Yatsu Yoichi Kataoka Jun Ikagawa Tomoko Kawai Nobuyuki Mizuno Tsunefumi Kamae Tsuneyoshi Tajima Hiroyasu Takahashi Tadayuki Saito Yoshitaka Gunji Shuichi

出版者

宇宙航空研究開発機構宇宙科学研究本部

雑誌

第4回宇宙科学シンポジウム = Proceedings of the 4th Space Science Symposium

巻号頁・発行日

pp.453-455, 2004-08

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X線、ガンマ線の偏光はほとんど全ての高エネルギー天文現象と関連し、その物理を研究するための有力なプローブである。しかしながら、これまでの観測例は10keV以下では1970年代のかに星雲、10keV以上ではガンマ線バーストのみである。そこで、30〜200keVの領域での世界初の偏光観測を目標とし気球実験を行う予定であり、これに搭載するためのWell-type硬X線偏光PoGO(Polarized Gamma-ray Observer)の開発を行っている。

著者

Koyama Katsuji Hyodo Yoshiaki Inui Tatsuya NAKAJIMA Hiroshi MATSUMOTO Hironori TSURU Takeshi Go TAKAHASHI Tadayuki MAEDA Yoshitomo YAMAZAKI Noriko Y. MURAKAMI Hiroshi YAMAUCHI Shigeo TSUBOI Yohko SENDA Atsushi KATAOKA Jun TAKAHASHI Hiromitsu HOLT Stephen S. BROWN Gregory V.

出版者

日本天文学会

雑誌

PASJ : publications of the Astronomical Society of Japan (ISSN:00046264)

巻号頁・発行日

vol.59, no.1, pp.S245-S255, 2007-01-31

被引用文献数

16 129

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We have observed the diffuse X-ray emission from the Galactic Center (GC) using the X-ray Imaging Spectrometer (XIS) on Suzaku. The high-energy resolution and the low-background orbit provided excellent spectra of the GC diffuse X-rays (GCDX). The XIS found many emission lines in the GCDX near the energy of K-shell transitions of iron and nickel. The most pronounced features are Fe I Kα at 6.4 keV and K-shell absorption edge at 7.1 keV, which are from neutral and/or low ionization states of iron, and the K-shell lines at 6.7 keV and 6.9 keV from He-like (Fe XXV Kα) and hydrogenic (Fe XXVI Lyα) ions of iron. In addition, Kα lines from neutral or low ionization nickel (Ni I Kα) and He-like nickel (Ni XXVII Kα), Fe I Kβ, Fe XXV Kβ, Fe XXVI Lyβ, Fe XXV Kγ and FeXXVI Lyγ were detected for the first time. The line center energies and widths of Fe XXV Kα and Fe XXVI Lyα favor a collisional excitation plasma for the origin of the GCDX. The electron temperature determined from the line flux ratio of Fe XXV Kα/Fe XXV Kβ is similar to the ionization temperature determined from that of Fe XXV Kα/Fe XXVI Lyα. Thus it would appear that the GCDX plasma is close to ionization equilibrium. The 6.7 keV flux and temperature distribution to the galactic longitude is smooth and monotonic, in contrast to the integrated point source flux distribution. These facts support the hypothesis that the GCDX is truly diffuse emission rather than the integration of the outputs of a large number of unresolved point sources. In addition, our results demonstrate that the chemical composition of Fe in the interstellar gas near the GC is constrained to be about 3.5 times solar abundance.