研究者業績

藤本 龍一

フジモト リュウイチ  (Ryuichi Fujimoto)

基本情報

所属
国立研究開発法人宇宙航空研究開発機構 宇宙科学研究所 宇宙物理学研究系 教授
総合研究大学院大学 先端学術院 宇宙科学コース 教授
東京科学大学 理学院 物理学系 特定教授
北海道大学 大学院理学院 宇宙理学専攻 客員教授
学位
博士(理学)(東京大学)
修士(東京大学)

研究者番号
20280555
ORCID ID
 https://orcid.org/0000-0002-2374-7073
J-GLOBAL ID
200901095989600566
researchmap会員ID
1000363020

X線マイクロカロリメータを用いた極低温精密X線分光装置の開発に取り組み,2023年9月打ち上げのXRISM衛星に搭載されたResolve観測装置として実現しました.

研究指導のテーマとしては,(1) XRISM衛星による精密X線分光観測データを解析し,銀河団ガスの運動を調べて,宇宙の大規模構造形成過程の理解を深める,(2) 宇宙マイクロ波背景放射の偏光観測を目指すLiteBIRD衛星を見据えた実験的研究を行なう等.特定の自然現象について理解を深めると同時に,複雑な自然現象の背景にある物理法則に至る過程を,実験・解析手法とともにしっかりと身につけてもらいたいと考えています.


学歴

 2

委員歴

 1

論文

 170
  • Fujimoto Ryuichi, Mitsuda Kazuhisa, McCammon Dan, TAKEI Yoh, BAUER Michael, ISHISAKI Yoshitaka, PORTER F. Scott, YAMAGUCHI Hiroya, HAYASHIDA Kiyoshi, YAMASAKI Noriko Y.
    Progress of theoretical physics. Supplement 59(169) 71-74 2007年  
    During the Suzaku north ecliptic pole observation of 2005 September 2-4, a long-term enhancement was observed, and the C VI 4p to 1s transition line at 459eV was apparently detected. The observed line intensity is comparable to that of the C VI 2p to 1s line at 367eV. This is strong evidence for the charge-exchange process. In addition, O VII, O VIII, Ne X, and Mg XI lines showed clear enhancements. There are also features in the 750-900eV range that could be due to some combination of Fe-L lines, higher order transitions of O VIII (3p to 1s and 6p to 1s), and a Ne IX line. From the correlation of the X-ray intensity with solar-wind flux on time scales of about half a day, and from the short-term (~10 minutes) variations of the X-ray intensity, these lines most likely arise from solar-wind heavy ions interacting with neutral material in the Earth's magnetosheath.
  • ISHISAKI Yoshitaka, MAEDA Yoshitomo, FUJIMOTO Ryuichi, OZAKI Masanobu, EBISAWA Ken, TAKAHASHI Tadayuki, UEDA Yoshihiro, OGASAKA Yasushi, PTAK Andrew, MUKAI Koji, HAMAGUCHI Kenji, HIRAYAMA Masaharu, KOTANI Taro, KUBO Hidetoshi, SHIBATA Ryo, EBARA Masatoshi, FURUZAWA Akihiro, IIZUKA Ryo, INOUE Hirohiko, MORI Hideyuki, OKADA Shunsaku, YOKOYAMA Yushi, MATSUMOTO Hironori, NAKAJIMA Hiroshi, YAMAGUCHI Hiroya, ANABUKI Naohisa, TAWA Noriaki, NAGAI Masaaki, KATSUDA Satoru, HAYASHIDA Kiyoshi, BAMBA Aya, MILLER Eric D., SATO Kosuke, YAMASAKI Noriko Y.
    PASJ : publications of the Astronomical Society of Japan 59(1 SPEC. ISS.) S113-S132 2007年  
  • Smith, R.K., Bautz, M.W., Edgar, R.J., Fujimoto, R., Hamaguchi, K., Hughes, J.P., Ishida, M., Kelley, R., Kllbourne, C.A., Kuntz, K.D., McCammon, D., Miller, E., Mitsuda, K., Mukai, K., Plucinsky, P.P., Porter, F.S., Snowden, S.L., Takei, Y., Terada, Y., Tsuboi, Y., Yamasaki, N.Y.
    Publications of the Astronomical Society of Japan 59(1 SPEC. ISS.) 2007年  
  • Shirron, P.J., DiPirro, M.J., Panek, J., Kelley, R., Mitsuda, K., Fujimoto, R., Hirabayashi, M., McCammon, D.
    Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 559(2) 2006年  
  • Yoshino, T., Yoshida, K., Hagihara, T., Sato, K., Morita, U., Ishisaki, Y., Fujimoto, R., Yamasaki, N.Y., Mitsuda, K.
    Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 559(2) 2006年  
  • Fujimoto, R., Mitsuda, K., Hirabayashi, M., Narasaki, K., Breon, S., Boyle, R., DiPirro, M., Volz, S.M., Kelley, R.L.
    Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 559(2) 2006年  
  • Ota, N., Inada, N., Oguri, M., Mitsuda, K., Richards, G.T., Suto, Y., Brandt, W.N., Castander, F.J., Fujimoto, R., Hall, P.B., Keeton, C.R., Nichol, R.C., Schneider, D.P., Eisenstein, D.E., Frieman, J.A., Turner, E.L., Minezaki, T., Yoshi, Y.
    Astrophysical Journal 647(1 I) 215-221 2006年  
    We present results from Chandra observations of SDSS J1004+4112, a strongly lensed quasar system with a maximum image separation of 15''. All four bright images of the quasar, as well as resolved X-ray emission originating from the lensing cluster, are clearly detected. The emission from the lensing cluster extends out to approximately 1'5. We measure the bolometric X-ray luminosity and temperature of the lensing cluster to be 4.7; 10(44) ergs s(-1) and 6.4 keV, consistent with the luminosity-temperature relation for distant clusters. The mass estimated from the X-ray observation shows excellent agreement with the mass derived from gravitational lensing. The X-ray flux ratios of the quasar images differ markedly from the optical flux ratios, and the combined X-ray spectrum of the images possesses an unusually strong Fe K alpha emission line, both of which are indicative of microlensing.
  • Kilbourne, C.A., Boyce, K.R., Brown, G.V., Cottam, J., Figueroa-Feliciano, E., Fujimoto, R., Furusho, T., Ishisaki, Y., Kelley, R.L., McCammon, D., Mitsuda, K., Morita, U., Porter, F.S., Ota, N., Saab, T., Takei, Y., Yamamoto, M.
    Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 559(2) 2006年  
  • Cottam, J., Boyce, K.R., Brown, G.V., Fujimoto, R., Furusho, T., Ishisaki, Y., Kelley, R.L., Kilbourne, C.A., McCammon, D., Mitsuda, K., Morita, U., Ota, N., Porter, F.S., Saab, T., Takei, Y., Yamamoto, M.
    Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 559(2) 2006年  
  • Ota, N., Boyce, K.R., Brown, G.V., Cottam, J., Fujimoto, R., Furusho, T., Ishisaki, Y., Kelley, R.L., Kilbourne, C.A., McCammon, D., Mitsuda, K., Morita, U., Porter, F.S., Takei, Y., Yamamoto, M.
    Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 559(2) 2006年  
  • Morita, U., Yamakawa, Y., Fujimori, T., Ishisaki, Y., Ohashi, T., Takei, Y., Yoshida, K., Yoshino, T., Mitsuda, K., Yamasaki, N.Y., Fujimoto, R., Sato, H., Minoura, Y., Takahashi, N., Homma, T., Shoji, S., Kuroda, Y., Onishi, M.
    Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 559(2) 2006年  
  • A Hayakawa, C Inoue, Y Ishisaki, M Ishida, T Ohashi, T Furusho, NY Yamasaki, R Fujimoto, K Mitsuda, K Misaki, Y Maeda, H Kunieda
    OPTICS FOR EUV, X-RAY AND GAMMA-RAY ASTRONOMY 5168 364-375 2004年  査読有り
    X-Ray Spectrometer (XRS) is the microcalorimeter onboard the X-ray astronomy satellite Astro-E2 which is scheduled to be launched early in 2005. For the XRS to achieve its best energy resolution of 6 eV at 6 keV, X-ray intensity should be limited up to several c s(-1) pixel(-1). The filter wheel (FW) is the instrument to reduce incident X-ray intensity on the XRS using extinction filters. The FW consists of a stepping motor, extinction filters, and a filter disk which has six mounting positions for the extinction filters. Among the six mounting points, two are used for Neutral Density (ND) filters, another two are for Beryllium (Be) filters, and the other two are remained open. The biggest modification from Astro-E is that we attach radioisotopes of Fe-55 and Ca-41 on the filter disk, which illuminate the XRS pixels to monitor the gain in orbit. We present here the mechanical design of the FW especially on improvements from Astro-E, and the results of our calibration measurements on X-ray transmission of the extinction filters.
  • Y Ishisaki, T Ohashi, T Oshima, U Morita, K Shinozaki, K Sato, K Mitsuda, NY Yamasaki, R Fujimoto, Y Takei, H Sato, N Takahashi, T Homma, T Osaka
    HIGH-ENERGY DETECTORS IN ASTRONOMY 5501 123-134 2004年  
    We are developing a superconducting transition-edge sensor (TES) microcalorimeter array for the Diffuse Intergalactic Oxygen Surveyor (DIOS) mission. DIOS is a relatively small Japanese X-ray mission which will study large-scale distribution of the warm-hot intergalactic medium (WHIM) using O-VII and O-VIII emission lines. The satellite weighs about 400 kg equipped with a four-reflection X-ray telescope (FXT) and a TES microcalorimeter array (XSA). The design goal of the observing system is an effective area larger than 100 cm 2 at the oxygen line energy, a field of view about 50 arcmin square, and an energy resolution about 2 eV in the energy range of 0.3-1 keV. The TES microcalorimeter array provides the large field of view and good energy resolution at the same time. We plan to install an array comprising 16 x 16 pixels with an overall size of 1 cm square, which is cooled with a cryogen-free cooler. Pixels are readout by multiplexing signals using a multi-input SQUID amplifier, with each input connected to a TES microcalorimeter which is AC biased with a different frequency. We report the design and present status of the XSA system development.
  • Kudo, H., Nakamura, T., Arakawa, T., Ohtsuka, S., Izumi, T., Shoji, S., Sato, S., Kobayashi, H., Mori, K., Homma, T., Osaka, T., Mitsuda, K., Yamasaki, N.Y., Fujimoto, R., Iyomoto, N., Oshima, T., Futamoto, K., Takei, Y., Ichitsubo, T., Fujimori, T., Ishisaki, Y., Morita, U., Koga, T., Sato, K., Ohashi, T., Kuroda, Y., Onishi, M., Otake, K., Beppu, F.
    Sensors and Actuators, A: Physical 114(2-3) 2004年  
  • Fujimoto, R., Mitsuda, K., Yamasaki, N.Y., Iyomoto, N., Oshima, T., Takei, Y., Futamoto, K., Ichitsubo, T., Fujimori, T., Yoshida, K., Ishisaki, Y., Morita, U., Koga, T., Shinozaki, K., Sato, K., Takai, N., Ohashi, T., Kudo, H., Sato, H., Arakawa, T., Kobayashi, H., Izumi, T., Ohtsuka, S., Mori, K., Shoji, S., Osaka, T., Homma, T., Kuroda, Y., Onishi, M., Goto, M., Beppu, F., Tanaka, T., Morooka, T., Nakayama, S., Chinone, K.
    Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 520(1-3) 2004年  
  • Takei, Y., Tanaka, K., Fujimoto, R., Ishisaki, Y., Morita, U., Morooka, T., Oshima, T., Futamoto, K., Hiroike, T., Koga, T., Mitsuda, K., Ohashi, T., Yamasaki, N.Y., Iyomoto, N., Ichitsubo, T., Sato, K., Fujimori, T., Shinozaki, K., Nakayama, S., Chinone, K.
    Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 523(1-2) 2004年  
  • Iyomoto, N., Ichitsubo, T., Mitsuda, K., Yamasaki, N.Y., Fujimoto, R., Oshima, T., Futamoto, K., Takei, Y., Fujimori, T., Yoshida, K., Ishisaki, Y., Morita, U., Koga, T., Shinozaki, K., Sato, K., Takai, N., Ohashi, T., Miyazaki, T., Nakayama, S., Tanaka, K., Morooka, T., Chinone, K.
    Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 520(1-3) 2004年  
  • Ishisaki, Y., Morita, U., Koga, T., Shinozaki, K., Sato, K., Takai, N., Ohashi, T., Arakawa, T., Kudo, H., Sato, H., Kobayashi, H., Izumi, T., Ohtsuka, S., Mori, K., Shoji, S., Osaka, T., Homma, T., Mitsuda, K., Yamasaki, N.Y., Fujimoto, R., Iyomoto, N., Oshima, T., Futamoto, K., Takei, Y., Ichitsubo, T., Fujimori, T., Yoshida, K., Kuroda, Y., Onishi, M., Goto, M., Beppu, F.
    Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 520(1-3) 2004年  
  • Arakawa, T., Kudo, H., Sato, H., Kobayashi, H., Izumi, T., Ohtsuka, S., Mori, K., Shoji, S., Osaka, T., Homma, T., Mitsuda, K., Yamasaki, N., Fujimoto, R., Iyomoto, N., Oshima, T., Futamoto, K., Takei, Y., Ichitsubo, T., Fujimori, T., Yoshida, K., Ishisaki, Y., Morita, U., Koga, T., Shinozaki, K., Sato, K., Takai, N., Ohashi, T., Kuroda, Y., Onishi, M., Goto, M., Beppu, F.
    Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 520(1-3) 456-459 2004年  
    We have developed multi-pixel TES microcalorimeters in order to realize high-energy resolution and X-ray imaging. A Sn absorber and a Bi absorber were formed on Si3N4 and SiO2 membrane using two-step exposure photolithography and electrodeposition. A FEM analysis was carried out to investigate the performance of the X-ray microabsorbers. In addition, a superconducting through-wafer interconnection was demonstrated considering the future X-ray imager using microcalorimeters. Detail of the fabrication techniques, characteristics and simulation results of two types of the microabsorbers, as well as those of the calorimeters are described. (C) 2003 Elsevier B.V. All rights reserved.
  • Yoshikawa Kohji, Dolag Klaus, Suto Yasushi, SASAKI Shin, YAMASAKI Noriko Y., OHASHI Takaya, MITSUDA Kazuhisa, TAWARA Yuzuru, FUJIMOTO Ryuichi, FURUSHO Tae, FURUZAWA Akihiro, ISHIDA Manabu, ISHISAKI Yoshitaka, TAKEI Yoh
    PASJ : publications of the Astronomical Society of Japan 56(6) 939-957 2004年  
  • Takei, Y., Fujimoto, R., Ishisaki, Y., Morita, U., Tanaka, K., Koga, T., Mitsuda, K., Ohashi, T., Yamasaki, N.Y., Iyomoto, N., Ichitsubo, T., Sato, K., Fujimori, T., Oshima, T., Futamoto, K., Shinozaki, K., Morooka, T., Nakayama, S., Yoshida, K., Takai, N., Chinone, K.
    Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 520(1-3) 2004年  
  • Kudo Hiroyuki, Arakawa Takahiro, Ohtsuka Shinichiro, Izumi Toshiyuki, Shoji Shuichi, Sato Hirotaka, Kobayashi Hideomi, Mori Kentaro, Homma Takayuki, Osaka Tetsuya, Iyomoto Naoko, Fujimoto Ryuichi, Mitsuda Kazuhisa, Yamasaki Noriko Y., Oshima Tai, Futamoto Kazuo, Takei Yoh, Ichitsubo Taro, Fujimori Tamayuki, Ishisaki Yoshitaka, Morita Umeyo, Koga Takeo, Shinozaki Keisuke, Sato Kousuke, Ohashi Takaya, Kuroda Yoshikatsu, Onishi Mitsunobu, Otake Kunio, Beppu Fumiaki
    Japanese journal of applied physics. Pt. 1, Regular papers & short notes 43(3) 1190-1195 2004年  
    An X-ray microcalorimeter is a cryogenic energy-dispersive spectrometer, which has an energy resolution almost comparable to that of conventional wavelength-dispersive spectrometers. Using a transition edge sensor (TES) as a temperature sensor, the energy resolution can be further improved. We have developed a new method of achieving an array of TES microcalorimeters for the purpose of X-ray imaging. To achieve this, mushroom-shaped X-ray microabsorbers formed using electrodeposition were applied. The temperature of the TES, which is easily degraded by thermal diffusion, was kept sufficiently low throughout the process to achieve practical use. On the bases of this new method, a $2\times 2$ ($\times$ 4) array of TES microcalorimeters was fabricated and tested. A high energy resolution of 13.0 eV at 6 keV was achieved and the filling factor was improved to 83%. Although several issues still need to be investigated, we verified that our method is useful for fabricating a Ti–Au TES microcalorimeter array.
  • Futamoto, K., Mitsuda, K., Takei, Y., Fujimoto, R., Yamasaki, N.Y.
    Astrophysical Journal 605(2 I) 2004年  
  • Sato, H., Kobayashi, H., Kudo, H., Izumi, T., Homma, T., Osaka, T., Shoji, S., Ishisaki, Y., Fujimoto, R., Mitsuda, K.
    Electrochemistry 72(6) 2004年  
  • H. Kudo, S. Ohtsuka, T. Arakawa, T. Izumi, S. Shoji, H. Sato, H. Kobayashi, K. Mori, T. Homma, T. Osaka, K. Mitsuda, N. Y. Yamasaki, R. Fujimoto, N. Iyomoto, T. Oshima, K. Futamoto, Y. Takei, T. Ichitsubo, T. Fujimori, Y. Ishisaki, U. Morita, T. Koga, K. Sato, T. Ohashi, Y. Kuroda, M. Onishi, K. Otake
    Digest of Papers - Microprocesses and Nanotechnology 2003 - 2003 International Microprocesses and Nanotechnology Conference, MNC 2003 182-183 2003年  査読有り
    In this paper we developed through-wafer interconnections using only a simple fabrication process. The interconnection was successfully transformed into the superconducting state. A current density of 13 cm/sup 2//mA was obtained in the superconducting state. We realize high energy-resolution X-ray imaging using the superconducting through-wafer interconnections.
  • Y Ishisaki, U Morita, T Koga, K Sato, T Ohashi, K Mitsuda, NY Yamasaki, R Fujimoto, N Iyomoto, T Oshima, K Futamoto, Y Takei, T Ichitsubo, T Fujimori, S Shoji, H Kudo, T Nakamura, T Arakawa, T Osaka, T Homma, H Sato, H Kobayashi, K Mori, K Tanaka, T Morooka, S Nakayama, K Chinone, Y Kuroda, M Onishi, K Otake
    X-RAY AND GAMMA-RAY TELESCOPES AND INSTRUMENTS FOR ASTRONOMY, PTS 1 AND 2 4851 831-841 2003年  
    We are developing a superconducting transition-edge sensor (TES) calorimeter for future Japanese X-ray astronomy missions (e.g. NeXT mission). The performance of our single pixel TES calorimeter is presented. We fabricated a Ti/Au (40 nm/110 nm) bilayer TES on a thin silicon-nitride membrane, which is adjusted to have a transition temperature of about 100 mK. The size of the TES is 500 mum x 500 mum, and 300 mum x 300 mum gold with a thickness of 300 nm is deposited with sputtering as an X-ray absorber. The TES calorimeter was installed in a dilution refrigerator operated at similar to 40 mK, with a combination of 400-series SQUID array as an ammeter. Collimated 5.9 keV X-rays (200 pm in diameter) from 55 Fe isotope were irradiated and X-ray pulses were obtained. Simultaneously with a fast falling time constant of 74.2 mus, the energy resolution of 6.6 +/- 0.4 eV was attained, while the baseline noise was 6.4 eV. The contents of the energy resolution are 5.1 eV of the excess noise, 3.3 eV of the readout noise, 1.6 eV of the pulse by pulse variation, and 1.9 eV of the intrinsic noise. The baseline noise are dominated by an unknown excess noise, which increases roughly in proportion to the inverse of the TES resistance. The pulse height is sensitive to the operating conditions, and the superconducting shield appears to have improved it by a factor of similar to 2. The calorimeter works fine over six months surviving five thermal cycles, even though it is kept in air.
  • N Iyomoto, T Ichitsubo, T Oshima, K Mitsuda, R Fujimoto, K Futamoto, Y Takei, T Fujimori, T Miyazaki, Y Ishisaki, T Hiroike, NY Yamasaki, T Koga, K Sato, T Ohashi, S Shoji, H Kudo, T Nakamura, T Arakawa, H Sato, H Kobayashi, T Homma, T Osaka, S Nakayama, T Morooka, K Chinone, K Tanaka, Y Kuroda, M Onishi, M Goto, U Morita
    X-RAY AND GAMMA-RAY TELESCOPES AND INSTRUMENTS FOR ASTRONOMY, PTS 1 AND 2 4851 965-974 2003年  
    We are developing a superconducting Transition-Edge Sensor (TES) calorimeter array. We adopt calorimeter multiplex in frequency domain to read signals from the calorimeter array with a small number of front-end electronics and wirings. We further utilize Calorimeter Bridge Biased by an AC Generator (CABBAGE) approach(1,2) to eliminate the AC carrier in the output. We tested the method using a TES calorimeter, which has a transition temperature of 390 mK. Because of the high operating temperature, energy resolution (DeltaE) of the calorimeter is limited to 200 eV at 5.9 keV even when it is biased with a DC current. We operated the calorimeter in CABBAGE circuit with 30 kHz sinusoidal bias and obtained DeltaE of 250 eV. We found that there remains a small-amplitude residual in the output even at the bridge balance point. The residual contains not only 30 kHz component but also odd-order harmonics. We consider that this is due to the variation of the TES resistor with the bias current. Some of the degradation of DeltaE from DC bias to AC bias can be explained by the fact that some of signal power is carried in the odd-order harmonics, which we did not utilize in the data reduction process. We also succeeded in operate the CABBAGE by 100 kHz, although DeltaE was degraded to 380 eV because of unstable bath temperature during the data acquisition and probably because of low response of the signal readout circuit at the frequency.
  • Tanaka, K., Morooka, T., Fujimoto, R., Ishisaki, Y., Takei, Y., Morita, U., Iyomoto, N., Oshima, T., Nakayama, S., Yamasaki, N., Koyanagi, M., Mitsuda, K., Ohashi, T., Chinone, K.
    Physica B: Condensed Matter 329-333(II) 2003年  
  • Boller, Th., Keil, R., Hasinger, G., Costantini, E., Fujimoto, R., Anabuki, N., Lehmann, I., Gallo, L.
    Astronomy and Astrophysics 411(2) 2003年  
  • Homma, T., Sato, H., Kobayashi, H., Arakawa, T., Kudo, H., Osaka, T., Shoji, S., Ishisaki, Y., Oshima, T., Iyomoto, N., Fujimoto, R., Mitsuda, K.
    Journal of Electroanalytical Chemistry 559 2003年  
  • Ebisawa, K., Fujimoto, R., Ueda, Y.
    Astronomische Nachrichten 324(1-2) 159-159 2003年  
  • H Kudo, H Sato, T Nakamura, T Arakawa, E Goto, S Shoji, T Homma, T Osaka, K Mitsuda, R Fujimoto, N Iyomoto, MD Audley, T Miyazaki, T Oshima, M Yamazaki, K Futamoto, Y Takei, Y Ishisaki, T Kagei, T Hiroike, T Ohashi, NY Yamasaki, A Kushino, Y Kuroda, M Onishi, M Goto
    LOW TEMPERATURE DETECTORS 605 235-238 2002年  査読有り
    For the next generation of astronomical X-ray imaging detectors, arrays with large numbers of microstructures (similar to1000 pixels) will be required. To meet this requirement, a tin absorber for an X-ray microcalorimeter, which has a so-called "mushroom" shape, is fabricated by electrodeposition and polishing. This method enables the fabrication of a large number of arrayed microcalorimeters. Details of the fabrication process, the characteristics of the absorber and the fabricated microcalorimeters are reported.
  • R Fujimoto, K Mitsuda, N Iyomoto, MD Audley, T Miyazaki, T Oshima, M Yamazaki, K Futamoto, Y Takei, Y Ishisaki, T Kagei, T Hiroike, U Morita, T Ohashi, NY Yamasaki, A Kushino, H Kudo, H Sato, T Nakamura, E Goto, S Shoji, T Homma, T Osaka, Y Kuroda, M Onishi, M Goto, K Tanaka, T Morooka, S Nakayama, K Chinone
    LOW TEMPERATURE DETECTORS 605 231-234 2002年  
    A superconducting phase-transition microcalorimeter is a promising detector for high resolution X-ray spectroscopy. We are developing such a detector for future Japanese X-ray astronomy missions. In our design, a tin absorber is electrodeposited as a mushroom structure to achieve a high covering fraction. We have succeeded in detecting X-rays with the first model of our calorimeter with an electrodeposited absorber, though the energy resolution was limited due to residual resist. We are also developing a phase-transition microcalorimeter with a low transition temperature. We describe the results of these experiments, and discuss the limiting factors of their performance.
  • T Miyazaki, M Yamazaki, K Futamoto, K Mitsuda, R Fujimoto, N Iyomoto, T Oshima, D Audley, Y Ishisaki, T Kagei, T Ohashi, N Yamasaki, S Shoji, H Kudo, Y Yokoyama
    LOW TEMPERATURE DETECTORS 605 313-316 2002年  
    In order to realize a large format (e.g. similar to 32 x 32) calorimeter array, it is essential to multiplex calorimeter signals at cryogenic temperatures without losing signal to noise ratio. For this purpose we propose a brand-new readout method, the CABBAGE ((ca) under bar lorimeter (B) under bar ridge (B) under bar iased by an (A) under barC Generator) where an AC biased calorimeters are placed in resistance bridges. In this paper we first describe the principles of CABBAGE and investigate its response and noise.We propose the large format calorimeter array readout using CABBAGEs, and discuss the new TES microcalorimeter readout method without using SQUIDs.
  • Takei, Y., Fujimoto, R., Mitsuda, K., Onaka, T.
    Astrophysical Journal 581(1 I) 2002年  
  • Morooka, T., Tanaka, K., Nagata, A., Nakayama, S., Chinone, K., Futamoto, K., Fujimoto, R., Mitsuda, K.
    Superconductor Science and Technology 15(1) 2002年  
  • N Anabuki, D Yonetoku, R Fujimoto, T Nakagawa
    NEW CENTURY OF X-RAY ASTRONOMY 251 292-293 2001年  査読有り
    We analyzed ASCA data of 28 luminous infrared galaxies including 16 ultraluminous infrared galaxies (ULIRGs) to study the nature of the AGN and to reveal the energy source of their far infrared luminosity. Our primary conclusion is that the circumnuclear starburst activity is the main energy source of most ULIRGs. We also found that the ULIRGs with unabsorbed AGN tend to have a narrow-line Seyfert I nucleus.
  • MD Audley, R Fujimoto, K Mitsuda, KA Arnaud, KC Gendreau, KR Boyce, CM Fleetwood, RL Kelley, RA Keski-Kuha, FS Porter, CK Stahle, AE Szymkowiak, JL Tveekrem, Y Ishisaki, T Mihara
    NEW CENTURY OF X-RAY ASTRONOMY 251 516-517 2001年  査読有り
    We describe the transmission calibration of the Astro-E XRS blocking filters. XRS was the prime instrument on board the Japanese-US ASTRO-E observatory which was lost due to a rocket failure. XRS's high spectral resolution makes us sensitive to fine structure in the X-ray absorption edges of the filters for the oxygen and aluminum edges around 0.5 and 1.5 keV. Thus, it is important that we measure these features on the ground. A spare XRS microcalorimeter is now being used for laboratory astrophysics at LLNL and it is hoped that future missions such as ASTRO-EII might carry similar detectors. We thus continue to calibrate the spare XRS optical blocking filters.
  • R Fujimoto, K Mitsuda, N Iyomoto, MD Audley, T Miyazaki, T Oshima, M Yamazaki, K Futamoto, Y Ishisaki, N Yamasaki, T Ohashi, T Kagei, A Kushino, T Hiroike, S Shoji, H Kudo, Y Yokoyama, H Sato, T Nakamura, E Gotoh, Y Kuroda, M Onishi, M Goto
    NEW CENTURY OF X-RAY ASTRONOMY 251 534-535 2001年  
    A superconducting phase-transition microcalorimeter is a promising detector for high resolution X-ray spectroscopy. We are developing such a detector for future Japanese X-ray astronomy missions. The outline and the status of our development are described.
  • Y Ishisaki, N Yamasaki, T Ohashi, T Kagei, T Miyazaki, K Mitsuda, R Fujimoto, N Iyomoto, T Oshima, M Yamazaki, K Futamoto, D Audley, S Shoji, H Kudo, Y Yokoyama
    NEW CENTURY OF X-RAY ASTRONOMY 251 548-549 2001年  
    Development of an X-ray microcalorimeter utilizing the superconducting transition edge sensor (TES) is under way. We fabricated a Ti-Au bilayer TES calorimeter on a sillicon wafer. A tin film of 0.5 x 0.5 x 0.015 mm was glued on it with epoxy as an absorber. Operating it at 100-200 mK, we successfully detected Mn Kalpha X-rays (5.9 keV) with the calorimeter, although the energy resolution was about 100 eV (FWHM).
  • T Oshima, M Yamazaki, K Mitsuda, R Fujimoto, N Iyomoto, MD Audley, T Miyazaki, K Futamoto, Y Ishisaki, N Yamasaki, T Ohashi, T Kagei, A Kushino, T Hiroike, S Shoji, H Kudo, Y Yokoyama
    NEW CENTURY OF X-RAY ASTRONOMY 251 584-585 2001年  
    A SQUID array amplifier and a 4-input SQUID array amplifier produced by SEIKO Instruments Inc. (SII) are used as readouts of our calorimeter system. Both achieve good performance with low noise (3-4 pA/rootHz). The 4-input SQUID array amplifier is a device that has recently been developed for multiplexing calorimeter signals, and is directly applicable to the AC multiplexing method. The performance of these SQUID array amplifiers is described.
  • Terada, Y., Ishida, M., Makishima, K., Imanari, T., Fujimoto, R., Matsuzaki, K., Kaneda, H.
    Monthly Notices of the Royal Astronomical Society 328(1) 2001年  
  • Oshima, T., Mitsuda, K., Fujimoto, R., Iyomoto, N., Futamoto, K., Hattori, M., Ota, N., Mori, K., Ikebe, Y., Miralles, J.M., Kneib, J.-P.
    Astrophysical Journal 563(2 PART 2) L103-L106 2001年  
    We present the X-ray energy spectrum of the lensed broad absorption line QSO H1413+117 (the Cloverleaf) at z = 2.56 observed with the Chandra X-ray observatory. We detected 293 photons in a 40 ks Advanced CCD Imaging Spectrometer (ACIS-S) observation. The X-ray image consists of four lensed image components, thus the photons are from the lensed QSO itself. The overall spectrum can be described with a power-law function heavily absorbed by neutral matter at a redshift consistent with the QSO redshift. This supports the idea that intrinsic absorption is significant for BAL QSOs. The spectral fit significantly (99% confidence) improves when we include an emission line. The centroid energy and intrinsic width (Gaussian sigma) of the line are 6.21 +/- 0.16 keV and 220(-130+)(270) eV (90% errors), respectively, in the QSO rest frame, assuming the absorbed power law as the continuum. The equivalent width of the line in the QSO rest frame is 960(-480)(+1400) eV. We suggest that the large equivalent width, the centroid energy, and the line broadness can be explained by iron K emission arising from X-ray reprocessing in the BAL flow, assuming it has a conical thin-sheet structure.
  • 満田 和久, 藤本 龍一
    日本物理學會誌 55(5) 340-348 2000年5月5日  
    大多数の放射線検出器は,放射線によるイオン化によって生じた電荷を何らかの方法で電気信号に変換し,放射線を検出する.これに対しマイクロカロリメータは,放射線の吸収により生じた熱を温度変化として検出する.我が国5番目のX線天文衛星ASTRO-E衛星には,高い検出効率と高いエネルギー分解能を兼ね備えたX線分光検出器としてX線マイクロカロリメータが衛星としては史上初めて搭載されている.ここでは,X線マイクロカロリメータの動作原理,ASTRO-Eに搭載される検出器の構造,素子を動作温度60mKに冷却する冷却システムについて解説する.最後に,地上試験で実証された検出器の性能と,その性能(~10eVのエネルギー分解能)により期待される宇宙観測の新しい展開について述べる.
  • Kelley, R.L., Audley, M.D., Boyce, K.R., Fujimoto, R., Gendreau, K.C., Ishisaki, Y., McCammon, D., Mihara, T., Mitsuda, K., Moseley, S.H., Mott, D.B., Porter, F.S., Stahle, C.K., Szymkowiak, A.E.
    Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 444(1) 2000年  
  • Fujimoto, R., Mitsuda, K., Miyazaki, T., Maegami, K., Aruga, Y., Oshima, T., Yamazaki, M., Shoji, S., Kudo, H., Yokoyama, Y., Mihara, T., Shimizu, H.M.
    Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 444(1) 180-183 2000年  
    By applying a transition edge sensor (TES) as the thermometer in an X-ray microcalorimeter, the intrinsic energy resolution is expected to be significantly improved. The extremely low intrinsic noise allows us to operate the calorimeter at temperatures as high as one can obtain by pumping liquid He-3 ( similar to 0.3 K) and still achieve an energy resolution comparable to conventional semiconducting microcalorimeters operating at similar to 60 mK (Delta E similar to 10 eV FWHM). Taking this advantage into account, we are developing a titanium/gold bilayer TES calorimeter fabricated on a silicon wafer. The transition temperature is about 0.5 K. We have succeeded in detecting X-ray photons from 3 to 25 keV, which proves that this TES calorimeter works in a wide energy range. The energy resolution is, however, still much worse than we expected - 550 eV (FWHM) at 5.9 keV. This is because the design parameters are not optimized. Several approaches to improve the performance are described. (C) 2000 Elsevier Science B.V. All rights reserved.
  • Yokoyama, Y., Shoji, S., Mitsuda, K., Fujimoto, R., Miyazaki, T., Oshima, T., Yamazaki, M., Iyomoto, N., Futamoto, K., Ishizaki, Y., Kagei, T.
    Proceedings of SPIE - The International Society for Optical Engineering 4230 58-65 2000年  
    An X-ray microcalorimeter that consists of an x-ray absorber to transfer the incident photon energy to the temperature rise, a temperature sensor to detect the temperature change and suspending beams for thermal isolation from the substrate have been fabricated. Titanium/Gold thin film transition edge sensor (TES) is used as the temperature sensor. We fabricated and tested the first prototype in the previous study and obtained the transition temperature of 0.52K, energy resolution of 550eV (FWHM) for 6keV radiation. These values were smaller than that of expected. We applied a Sn absorber and redesigned the microstructure of the x-ray microcalorimeter. Consequently, we have obtained 158eV at 5.9keV radiation of the energy resolution, which is about 4 times higher than that of the first prototype. This value is nearly equal to the conventional X-ray CCD. The highest energy resolution of the x-ray microcalorimeter of our design is estimated to similar to5 eV at the operating point of 0.2K. To realize such a good energy resolution calorimeter array, we are going to improve the sensitivity of the TES by optimizing the process condition. A Sn absorber formed by electroplating is also under evaluating simultaneously. It is necessary to fabricate uniform array structures.
  • Gotthelf, E.V., Ueda, Y., Fujimoto, R., Kii, T., Yamaoka, K.
    Astrophysical Journal 543(1 PART 1) 2000年  
  • Hiroyuki Kudo, Yuichi Yokoyama, Shuichi Shoji, Tohru Oshima, Youichi Aruga, Kana Maegami, Ryuichi Fujimoto, Miyazaki Toshiyuki, Kazuhisa Mitsuda
    Proceedings of SPIE - The International Society for Optical Engineering 3893 241-249 1999年  
    A prototype of an X-ray microcalorimeter using Titanium/Gold transition edge sensor (TES) for detecting cosmic rays is fabricated and tested. This paper reports first experimental result of the prototype. By using silicon bulk micromachining, freestanding microstructure suspended with fine beams are obtained to achieve thermal isolation from the substrate. A superconductor, Ti in this case, can be used as a very sensitive temperature sensor at the narrow temperature range around its transition temperature. At the low temperatures below 1 K, the microstructure with very small heat capacity is expected to be thermally detecting single photons. Design consideration to realize radiation detection with extremely good energy resolution has been taken place. Our tentative goal is to obtain the energy resolution of 20 eV for 10 keV radiation at 0.5 K. We have fabricated a test device of the TES. The sensitivity of it is larger than 1000, which is enough for this purpose. The energy resolution of the prototype of the X-ray microcalorimeter was 550 eV (FWHM) for 6 keV radiation at approximately 0.5 K. This value is smaller than that expected. An optimization of the TES features is still necessary for a good energy resolution.
  • T Nakagawa, T Kii, R Fujimoto, T Miyazaki, H Inoue, Y Ogasaka, K Arnaud, R Kawabe
    GALAXY INTERACTIONS AT LOW AND HIGH REDSHIFT (186) 341-344 1999年  査読有り

MISC

 131
  • 佐藤浩介, 大橋隆哉, 石崎欣尚, 江副祐一郎, 山田真也, 山崎典子, 満田和久, 石田学, 前田良知, 田原譲, 三石郁之, 藤本龍一, 鶴剛, 太田直美, 大里健, 中島真也
    日本天文学会年会講演予稿集 2018 225 2018年8月20日  
  • 江副祐一郎, 石崎欣尚, 藤本龍一, 竹井洋, 石川久美, 安田進, 柳瀬慶一, 山崎典子, 佐藤浩介, 北本俊二, 小山志勇, 野田博文, 吉田誠至, 金尾憲一, 恒松正二, KELLEY R. L., KILBOURNE C. A., DIPIRRO M. J., SHIRRON P.
    日本天文学会年会講演予稿集 2018 2018年  
  • Alle, S.W., Aharonian, F., Akamatsu, H., Akimoto, F., Allen, S.W., Angelini, L., Audard, M., Awaki, H., Axelsson, M., Bamba, A., Bautz, M.W., Blandford, R., Brenneman, L.W., Brown, G.V., Bulbul, E., Cackett, E.M., Chernyakova, M., Chiao, M.P., Coppi, P.S., Costantini, E., De Plaa, J., De Vries, C.P., Den Herder, J.-W., Done, C., Dotani, T., Ebisawa, K., Eckart, M.E., Enoto, T., Ezoe, Y., Fabian, A.C., Ferrigno, C., Foster, A.R., Fujimoto, R., Fukazawa, Y., Furuzawa, A., Galeazzi, M., Gallo, L.C., Gandhi, P., Giustini, M., Goldwurm, A., Gu, L., Guainazzi, M., Haba, Y., Hagino, K., Hamaguchi, K., Harrus, I.M., Hatsukade, I., Hayashi, K., Hayashi, T., Hayashida, K., Hiraga, J.S., Hornschemeier, A., Hoshino, A., Hughes, J.P., Ichinohe, Y., Iizuka, R., Inoue, H., Inoue, Y., Ishida, M., Ishikawa, K., Ishisaki, Y., Iwai, M., Kaastra, J., Kallman, T., Kamae, T., Kataoka, J., Katsuda, S., Kawai, N., Kelley, R.L., Kilbourne, C.A., Kitaguchi, T., Kitamoto, S., Kitayama, T., Kohmura, T., Kokubun, M., Koyama, K., Koyama, S., Kretschmar, P., Krimm, H.A., Kubota, A., Kunieda, H., Laurent, P., Lee, S.-H., Leutenegger, M.A., Limousin, O.O., Loewenstein, M., Long, K.S., Lumb, D., Madejski, G., Maeda, Y., Maier, D., Makishima, K., Markevitch, M., Matsumoto, H., Matsushita, K., Mccammon, D., Mcnamara, B.R., Mehdipour, M., Miller, E.D., Miller, J.M., Mineshige, S., Mitsuda, K., Mitsuishi, I., Miyazawa, T., Mizuno, T., Mori, H., Mori, K., Mukai, K., Murakami, H., Mushotzky, R.F., Nakagawa, T., Nakajima, H., Nakamori, T., Nakashima, S., Nakazawa, K., Nobukawa, K.K., Nobukawa, M., Noda, H., Odaka, H., Ohashi, T., Ohno, M., Okajima, T., Ota, N., Ozaki, M., Paerels, F., Paltani, S., Petre, R., Pinto, C., Porter, F.S., Pottschmidt, K., Reynolds, C.S., Safi-Harb, S., Saito, S., Sakai, K., Sasaki, T., Sato, G., Sato, K., Sato, R., Sawada, M., Schartel, N., Serlemtsos, P.J., Seta, H., Shidatsu, M., Simionescu, A., Smith, R.K., Soong, Y., Stawarz, Ł., Sugawara, Y., Sugita, S., Szymkowiak, A., Tajima, H., Takahashi, H., Takahashi, T., Takeda, S., Takei, Y., Tamagawa, T., Tamura, T., Tanaka, T., Tanaka, Y., Tanaka, Y.T., Tashiro, M.S., Tawara, Y., Terada, Y., Terashima, Y., Tombesi, F., Tomida, H., Tsuboi, Y., Tsujimoto, M., Tsunemi, H., Suru, T.G., Uchida, H., Uchiyama, H., Uchiyama, Y., Ueda, S., Ueda, Y., Uno, S., Urry, C.M., Ursino, E., Watanabe, S., Werner, N., Wilkins, D.R., Williams, B.J., Yamada, S., Yamaguchi, H., Yamaoka, K., Yamasaki, N.Y., Yamauchi, M., Yamauchi, S., Yaqoob, T., Yatsu, Y., Yonetoku, D., Zhuravleva, I., Zoghbi, A., Nakaniwa, N.
    Publications of the Astronomical Society of Japan 70(2) 2018年  
    We report a Hitomi observation of IGR J16318-4848, a high-mass X-ray binary<br /> system with an extremely strong absorption of N_H~10^{24} cm^{-2}. Previous<br /> X-ray studies revealed that its spectrum is dominated by strong fluorescence<br /> lines of Fe as well as continuum emission. For physical and geometrical insight<br /> into the nature of the reprocessing material, we utilize the high spectroscopic<br /> resolving power of the X-ray microcalorimeter (the soft X-ray spectrometer;<br /> SXS) and the wide-band sensitivity by the soft and hard X-ray imager (SXI and<br /> HXI) aboard Hitomi. Even though photon counts are limited due to unintended<br /> off-axis pointing, the SXS spectrum resolves Fe K{\alpha_1} and K{\alpha_2}<br /> lines and puts strong constraints on the line centroid and width. The line<br /> width corresponds to the velocity of 160^{+300}_{-70} km s^{-1}. This<br /> represents the most accurate, and smallest, width measurement of this line made<br /> so far from any X-ray binary, much less than the Doppler broadening and shift<br /> expected from speeds which are characteristic of similar systems. Combined with<br /> the K-shell edge energy measured by the SXI and HXI spectra, the ionization<br /> state of Fe is estimated to be in the range of Fe I--IV. Considering the<br /> estimated ionization parameter and the distance between the X-ray source and<br /> the absorber, the density and thickness of the materials are estimated. The<br /> extraordinarily strong absorption and the absence of a Compton shoulder<br /> component is confirmed. These characteristics suggest reprocessing materials<br /> which are distributed in a narrow solid angle or scattering primarily with warm<br /> free electrons or neutral hydrogen.
  • Aharonian, F., Akamatsu, H., Akimoto, F., Allen, S.W., Angelini, L., Audard, M., Awaki, H., Axelsson, M., Bamba, A., Bautz, M.W., Blandford, R., Brenneman, L.W., Brown, G.V., Bulbul, E., Cackett, E.M., Chernyakova, M., Chiao, M.P., Coppi, P.S., Costantini, E., De Plaa, J., De Vries, C.P., Den Herder, J.-W., Done, C., Dotani, T., Ebisawa, K., Eckart, M.E., Enoto, T., Ezoe, Y., Fabian, A.C., Ferrigno, C., Foster, A.R., Fujimoto, R., Fukazawa, Y., Furuzawa, A., Galeazzi, M., Gallo, L.C., Gandhi, P., Giustini, M., Goldwurm, A., Gu, L., Guainazzi, M., Haba, Y., Hagino, K., Hamaguchi, K., Harrus, I.M., Hatsukade, I., Hayashi, K., Hayashi, T., Hayashida, K., Hiraga, J.S., Hornschemeier, A., Hoshino, A., Hughes, J.P., Ichinohe, Y., Iizuka, R., Inoue, H., Inoue, Y., Ishida, M., Ishikawa, K., Ishisaki, Y., Iwai, M., Kaastra, J., Kallman, T., Kamae, T., Kataoka, J., Katsuda, S., Kawai, N., Kelley, R.L., Kilbourne, C.A., Kitaguchi, T., Kitamoto, S., Kitayama, T., Kohmura, T., Kokubun, M., Koyama, K., Koyama, S., Kretschmar, P., Krimm, H.A., Kubota, A., Kunieda, H., Laurent, P., Lee, S.-H., Leutenegger, M.A., Limousin, O., Loewenstein, M., Long, K.S., Lumb, D., Madejski, G., Maeda, Y., Maier, D., Makishima, K., Markevitch, M., Matsumoto, H., Matsushita, K., McCammon, D., McNamara, B.R., Mehdipour, M., Miller, E.D., Miller, J.M., Mineshige, S., Mitsuda, K., Mitsuishi, I., Miyazawa, T., Mizuno, T., Mori, H., Mori, K., Mukai, K., Murakami, H., Mushotzky, R.F., Nakagawa, T., Nakajima, H., Nakamori, T., Nakashima, S., Nakazawa, K., Nobukawa, K.K., Nobukawa, M., Noda, H., Odaka, H., Ohashi, T., Ohno, M., Okajima, T., Ota, N., Ozaki, M., Paerels, F., Paltani, S., Petre, R., Pinto, C., Porter, F.S., Pottschmidt, K., Reynolds, C.S., Safi-Harb, S., Saito, S., Sakai, K., Sasaki, T., Sato, G., Sato, K., Sato, R., Sawada, M., Schartel, N., Serlemtsos, P.J., Seta, H., Shidatsu, M., Simionescu, A., Smith, R.K., Soong, Y., Stawarz, L., Sugawara, Y., Sugita, S., Szymkowiak, A., Tajima, H., Takahashi, H., Takahashi, T., Takeda, S., Takei, Y., Tamagawa, T., Tamura, T., Tanaka, T., Tanaka, Y., Tanaka, Y.T., Tashiro, M.S., Tawara, Y., Terada, Y., Terashima, Y., Tombesi, F., Tomida, H., Tsuboi, Y., Tsujimoto, M., Tsunemi, H., Tsuru, T.G., Uchida, H., Uchiyama, H., Uchiyama, Y., Ueda, S., Ueda, Y., Uno, S., Urry, C.M., Ursino, E., Watanabe, S., Werner, N., Wilkins, D.R., Williams, B.J., Yamada, S., Yamaguchi, H., Yamaoka, K., Yamasaki, N.Y., Yamauchi, M., Yamauchi, S., Yaqoob, T., Yatsu, Y., Yonetoku, D., Zhuravleva, I., Zoghbi, A., Uchida, Y.
    Publications of the Astronomical Society of Japan 70(6) 2018年  
    We present the results from the Hitomi Soft Gamma-ray Detector (SGD)<br /> observation of the Crab nebula. The main part of SGD is a Compton camera, which<br /> in addition to being a spectrometer, is capable of measuring polarization of<br /> gamma-ray photons. The Crab nebula is one of the brightest X-ray / gamma-ray<br /> sources on the sky, and, the only source from which polarized X-ray photons<br /> have been detected. SGD observed the Crab nebula during the initial test<br /> observation phase of Hitomi. We performed the data analysis of the SGD<br /> observation, the SGD background estimation and the SGD Monte Carlo simulations,<br /> and, successfully detected polarized gamma-ray emission from the Crab nebula<br /> with only about 5 ks exposure time. The obtained polarization fraction of the<br /> phase-integrated Crab emission (sum of pulsar and nebula emissions) is (22.1<br /> $\pm$ 10.6)% and, the polarization angle is 110.7$^o$ + 13.2 / $-$13.0$^o$ in<br /> the energy range of 60--160 keV (The errors correspond to the 1 sigma<br /> deviation). The confidence level of the polarization detection was 99.3%. The<br /> polarization angle measured by SGD is about one sigma deviation with the<br /> projected spin axis of the pulsar, 124.0$^o$ $\pm$0.1$^o$.
  • Aharonian, F., Akamatsu, H., Akimoto, F., Allen, S.W., Angelini, L., Audard, M., Awaki, H., Axelsson, M., Bamba, A., Bautz, M.W., Blandford, R., Brenneman, L.W., Brown, G.V., Bulbul, E., Cackett, E.M., Chernyakova, M., Chiao, M.P., Coppi, P.S., Costantini, E., De Plaa, J., De Vries, C.P., Den Herder, J.-W., Done, C., Dotani, T., Ebisawa, K., Eckart, M.E., Enoto, T., Ezoe, Y., Fabian, A.C., Ferrigno, C., Foster, A.R., Fujimoto, R., Fukazawa, Y., Furukawa, M., Furuzawa, A., Galeazzi, M., Gallo, L.C., Gandhi, P., Giustini, M., Goldwurm, A., Gu, L., Guainazzi, M., Haba, Y., Hagino, K., Hamaguchi, K., Harrus, I.M., Hatsukade, I., Hayashi, K., Hayashi, T., Hayashida, K., Hiraga, J.S., Hornschemeier, A., Hoshino, A., Hughes, J.P., Ichinohe, Y., Iizuka, R., Inoue, H., Inoue, Y., Ishida, M., Ishikawa, K., Ishisaki, Y., Iwai, M., Kaastra, J., Kallman, T., Kamae, T., Kataoka, J., Kato, Y., Katsuda, S., Kawai, N., Kelley, R.L., Kilbourne, C.A., Kitaguchi, T., Kitamoto, S., Kitayama, T., Kohmura, T., Kokubun, M., Koyama, K., Koyama, S., Kretschmar, P., Krimm, H.A., Kubota, A., Kunieda, H., Laurent, P., Lee, S.-H., Leutenegger, M.A., Limousin, O., Loewenstein, M., Long, K.S., Lumb, D., Madejski, G., Maeda, Y., Maier, D., Makishima, K., Markevitch, M., Matsumoto, H., Matsushita, K., McCammon, D., McNamara, B.R., Mehdipour, M., Miller, E.D., Miller, J.M., Mineshige, S., Mitsuda, K., Mitsuishi, I., Miyazawa, T., Mizuno, T., Mori, H., Mori, K., Mukai, K., Murakami, H., Mushotzky, R.F., Nakagawa, T., Nakajima, H., Nakamori, T., Nakashima, S., Nakazawa, K., Nobukawa, K.K., Nobukawa, M., Noda, H., Odaka, H., Ohashi, T., Ohno, M., Okajima, T., Ota, N., Ozaki, M., Paerels, F., Paltani, S., Petre, R., Pinto, C., Porter, F.S., Pottschmidt, K., Reynolds, C.S., Safi-Harb, S., Saito, S., Sakai, K., Sasaki, T., Sato, G., Sato, K., Sato, R., Sawada, M., Schartel, N., Serlemtsos, P.J., Seta, H., Shidatsu, M., Simionescu, A., Smith, R.K., Soong, Y., Stawarz, Ł., Sugawara, Y., Sugita, S., Szymkowiak, A., Tajima, H., Takahashi, H., Takahashi, T., Takeda, S., Takei, Y., Tamagawa, T., Tamura, T., Tanaka, T., Tanaka, Y., Tanaka, Y.T., Tashiro, M.S., Tawara, Y., Terada, Y., Terashima, Y., Tombesi, F., Tomida, H., Tsuboi, Y., Tsujimoto, M., Tsunemi, H., Tsuru, T.G., Uchida, H., Uchiyama, H., Uchiyama, Y., Ueda, S., Ueda, Y., Uno, S., Urry, C.M., Ursino, E., Watanabe, S., Werner, N., Wilkins, D.R., Williams, B.J., Yamada, S., Yamaguchi, H., Yamaoka, K., Yamasaki, N.Y., Yamauchi, M., Yamauchi, S., Yaqoob, T., Yatsu, Y., Yonetoku, D., Zhuravleva, I., Zoghbi, A.
    Publications of the Astronomical Society of Japan 70(2) 2018年  
    The present paper investigates the temperature structure of the X-ray<br /> emitting plasma in the core of the Perseus cluster using the 1.8--20.0 keV data<br /> obtained with the Soft X-ray Spectrometer (SXS) onboard the Hitomi Observatory.<br /> A series of four observations were carried out, with a total effective exposure<br /> time of 338 ks and covering a central region $\sim7&#039;$ in diameter. The SXS was<br /> operated with an energy resolution of $\sim$5 eV (full width at half maximum)<br /> at 5.9 keV. Not only fine structures of K-shell lines in He-like ions but also<br /> transitions from higher principal quantum numbers are clearly resolved from Si<br /> through Fe. This enables us to perform temperature diagnostics using the line<br /> ratios of Si, S, Ar, Ca, and Fe, and to provide the first direct measurement of<br /> the excitation temperature and ionization temperature in the Perseus cluster.<br /> The observed spectrum is roughly reproduced by a single temperature thermal<br /> plasma model in collisional ionization equilibrium, but detailed line ratio<br /> diagnostics reveal slight deviations from this approximation. In particular,<br /> the data exhibit an apparent trend of increasing ionization temperature with<br /> increasing atomic mass, as well as small differences between the ionization and<br /> excitation temperatures for Fe, the only element for which both temperatures<br /> can be measured. The best-fit two-temperature models suggest a combination of 3<br /> and 5 keV gas, which is consistent with the idea that the observed small<br /> deviations from a single temperature approximation are due to the effects of<br /> projection of the known radial temperature gradient in the cluster core along<br /> the line of sight. Comparison with the Chandra/ACIS and the XMM-Newton/RGS<br /> results on the other hand suggests that additional lower-temperature components<br /> are present in the ICM but not detectable by Hitomi SXS given its 1.8--20 keV<br /> energy band.

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