研究者業績

坂尾 太郎

サカオ タロウ  (Taro Sakao)

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 准教授
学位
博士(理学)(東京大学)

ORCID ID
 https://orcid.org/0000-0003-2991-4159
J-GLOBAL ID
200901017841696830
researchmap会員ID
5000019450

X線観測を中心に、飛翔体を用いた太陽物理学の研究を行なっています。

「ひので」、「ようこう」、SDOなどの衛星に搭載されたX線望遠鏡やEUV望遠鏡をはじめとする、飛翔体観測機器のデータを用いて、太陽フレアで発生するプラズマ粒子の爆発的な加熱と加速や、それらの惑星間空間への影響など、コロナ中のプラズマ活動現象の理解をめざします。

また、「ようこう」の硬X線望遠鏡HXTや「ひので」のX線望遠鏡XRTなど、新しい観測を可能とする装置開発を手がけており、現在は、将来の太陽高エネルギープラズマの研究に向けた、高空間分解能・低散乱性能を持つX線斜入射ミラーや、光子計測型の高速X線ピクセル検出器などの開発研究、および将来の飛翔体ミッションの検討を進めています。


I have been engaged in solar physics research with space and sub-orbital observations chiefly in X-ray wavelengths.

By use of data from instruments such as X-ray or EUV telescopes aboard Hinode, Yohkoh, and SDO, I aim to understand plasma activities in the solar corona, including explosive heating and acceleration of coronal plasmas during flares and their interplanetary consequences.

Meanwhile, I have participated in the development of instruments which make possible new observations of the solar corona; e.g., Hard X-ray Telescope (HXT) aboard Yohkoh and X-Ray Telescope (XRT) aboard Hinode. Currently, I am working on research and development of grazing-incidence X-ray mirrors (Wolter mirrors) of high spatial resolution/low scattering performance as well as photon-counting-type high-speed X-ray pixel detectors, together with studies on future space solar X-ray missions.


論文

 121
  • Mitsuo Oka, Amir Caspi, Bin Chen, Mark Cheung, James Drake, Dale Gary, Lindsay Glesener, Fan Guo, Hantao Ji, Xiaocan Li, Takuma Nakamura, Noriyuki Narukage, Katharine K. Reeves, Pascal Saint-Hilaire, Taro Sakao, Chengcai Shen, Amy WInebarger, Thomas Woods
    Bulletin of the American Astronomical Society 55(3) (10pp) 2023年7月31日  
    Heliophysics 2024 Decadal Whitepapers
  • Donguk Song, Ryohko Ishikawa, Ryouhei Kano, David E. McKenzie, Javier Trujillo Bueno, Frederic Auchere, Laurel A. Rachmeler, Takenori J. Okamoto, Masaki Yoshida, Ken Kobayashi, Christian Bethge, Hirohisa Hara, Kazuya Shinoda, Toshifumi Shimizu, Yoshinori Suematsu, Bart De Pontieu, Amy Winebarger, Noriyuki Narukage, Masahito Kubo, Taro Sakao, Andres Asensio Ramos, Luca Belluzzi, Jiri Stepan, Mats Carlsson, Tanausu del Pino Aleman, Ernest Alsina Ballester, Genevieve D. Vigil, Jorrit Leenaarts
    SOLAR PHYSICS 297(10) 2022年10月  査読有り
    We have developed an advanced UV spectropolarimeter called Chromospheric LAyer SpectroPolarimeter (CLASP2), aimed at achieving very high accuracy measurements (<0.1% at 3 sigma) of the linear (Q/I and U/I) and circular (V/I) polarizations of the Mg II h and k lines (280 nm). CLASP2 was launched on board a NASA sounding rocket on April 11, 2019. It successfully detected the full Stokes vector in an active-region plage and in the quiet Sun near the limb across the Mg II h and k lines for the first time. To verify the polarization characteristics of CLASP2, the response matrix is estimated by combining the results obtained from the preflight calibration on the ground, with the results of the inflight calibration acquired at the solar-disk center. We find that the response matrix of CLASP2 in the Mg II h and k lines is notably close to an ideal response matrix, i.e., the scale factor and the crosstalk terms are close to 1 and 0, respectively. Moreover, the uncertainty of each Stokes parameter estimated by the repeatability of the measurements is verified to be within the required tolerance. Based on our investigation, we conclude that CLASP2 achieves 0.1% polarization accuracy at a 3 sigma level.
  • L. A. Rachmeler, J. Trujillo Bueno, D. E. McKenzie, R. Ishikawa, F. Auchère, K. Kobayashi, R. Kano, T. J. Okamoto, C. W. Bethge, D. Song, E. Alsina Ballester, L. Belluzzi, T. del Pino Alemán, A. Asensio Ramos, M. Yoshida, T. Shimizu, A. Winebarger, A. R. Kobelski, G. D. Vigil, B. De Pontieu, N. Narukage, M. Kubo, T. Sakao, H. Hara, Y. Suematsu, J. Štěpán, M. Carlsson, J. Leenaarts
    The Astrophysical Journal 936(1) 67-67 2022年8月31日  査読有り
  • M. Bröse, A. Warmuth, T. Sakao, Y. Su
    Astronomy Astrophysics 663 A18-A18 2022年7月4日  査読有り
  • Ryohko Ishikawa, Javier Trujillo Bueno, Tanausu Del Pino Aleman, Takenori J. Okamoto, David E. McKenzie, Frederic Auchere, Ryouhei Kano, Donguk Song, Masaki Yoshida, Laurel A. Rachmeler, Ken Kobayashi, Hirohisa Hara, Masahito Kubo, Noriyuki Narukage, Taro Sakao, Toshifumi Shimizu, Yoshinori Suematsu, Christian Bethge, Bart De Pontieu, Alberto Sainz Dalda, Genevieve D. Vigil, Amy Winebarger, Ernest Alsina Ballester, Luca Belluzzi, Jiri Štepan, Andres Asensio Ramos, Mats Carlsson, Jorrit Leenaarts
    Science Advances 7(8) 2021年2月19日  査読有り
    Copyright © 2021 The Authors, some rights reserved. Routine ultraviolet imaging of the Sun's upper atmosphere shows the spectacular manifestation of solar activity; yet, we remain blind to its main driver, the magnetic field. Here, we report unprecedented spectropolarimetric observations of an active region plage and its surrounding enhanced network, showing circular polarization in ultraviolet (Mg ii h & k and Mn i) and visible (Fe i) lines. We infer the longitudinal magnetic field from the photosphere to the very upper chromosphere. At the top of the plage chromosphere, the field strengths reach more than 300 G, strongly correlated with the Mg ii k line core intensity and the electron pressure. This unique mapping shows how the magnetic field couples the different atmospheric layers and reveals the magnetic origin of the heating in the plage chromosphere.

MISC

 59

書籍等出版物

 3

講演・口頭発表等

 180

担当経験のある科目(授業)

 12
  • 2023年11月 - 2023年11月
    宇宙理学概論  (総合研究大学院大学・先端学術院・宇宙科学コース)
  • 2022年10月 - 2023年1月
    太陽物理学特論IV  (東京大学・理学系研究科・天文学専攻)
  • 2022年4月 - 2022年7月
    宇宙環境科学特論  (総合研究大学院大学・物理科学研究科・宇宙科学専攻)
  • 2021年11月 - 2021年11月
    宇宙理学概論  (総合研究大学院大学・物理科学研究科・宇宙科学専攻)
  • 2020年10月 - 2021年2月
    宇宙環境科学特論  (総合研究大学院大学・物理科学研究科・宇宙科学専攻)

Works(作品等)

 1

共同研究・競争的資金等の研究課題

 17

学術貢献活動

 43

社会貢献活動

 48

● 専任大学名

 1
  • 専任大学名
    総合研究大学院大学(SOKENDAI)

● 所属する所内委員会

 1
  • 所内委員会名
    放射線安全委員会