Direct measurement of cosmic-ray acceleration limit in supernovae

• Project Area: Exploration of Particle Physics and Cosmology with Neutrinos
• Project/Area Number: 19H05112
• Research Category: Grant-in-Aid for Scientific Research on Innovative Areas (Research in a proposed research area)
• Allocation Type: Single-year Grants
• Review Section: Science and Engineering
• Research Institution: The University of Tokyo (2020); Waseda University (2019)
• Principal Investigator: 浅岡 陽一 東京大学, 宇宙線研究所, 特任准教授 (40345054)
• Project Period (FY): 2019-04-01 – 2021-03-31
• Project Status: Completed (Fiscal Year 2020)
• Budget Amount: ¥4,290,000 (Direct Cost: ¥3,300,000、Indirect Cost: ¥990,000); Fiscal Year 2020: ¥2,080,000 (Direct Cost: ¥1,600,000、Indirect Cost: ¥480,000); Fiscal Year 2019: ¥2,210,000 (Direct Cost: ¥1,700,000、Indirect Cost: ¥510,000)
• Keywords: CALET / 銀河宇宙線 / 加速限界 / 超新星 / 陽子・ヘリウム

Outline of Research at the Start

超新星残骸における衝撃波加速は電荷に比例した加速限界を予言する．超新星残骸で達成可能な最高エネルギーは典型的に，陽子で60TeV (10の12乗電子ボルト)と見積られている．一方，宇宙線スペクトルの地上観測では，3000TeV付近で冪の折れ曲がり"knee"が見られる．"knee"は陽子の加速限界と捉えられており，地上からの観測に基づく理解と，超新星残骸モデルは整合的ではない．
本研究では5 年間のCALET データを用いて，100 TeV 領域に至る陽子・ヘリウムスペクトルを決定することで，上記の不整合を解決する鍵であり未検出の場合も重要な結果となる，電荷に比例する加速限界の検出を目指す．

Outline of Annual Research Achievements

国際宇宙ステーション搭載の高エネルギー宇宙線観測装置CALETは，2020年度も安定した軌道上運用を続け，観測データを蓄積した．それと同時に，さらに安定観測を継続してスペクトルの精度を向上させるため，軌道上運用の更なる効率化を実施した．軌道上CALETの長期安定運用は，統計が最も重要となる100TeV領域のスペクトルの精度を確保するために必須である．
2020年度の大きな成果として、CALETによる核子あたり2.2TeVまでの炭素及び酸素スペクトルの発表が挙げられる．本論文はPhysical Review Lettersに掲載された．核子あたり約200GeVの領域でスペクトルの硬化を3σ以上の有意性で観測した．宇宙線中の核子成分，特に超新星残骸にて加速されると考えられている，陽子，ヘリウム，炭素，酸素といった一次成分に関しては，統一的な理解が求められる．同一の検出器にて陽子に続きスペクトル硬化を検出したことは，銀河宇宙線核子成分の理解において重要な役割を果たす．
CALETは電子観測に最適化されており，エネルギー測定のために検出器内でのハドロン相互作用を必要とする陽子やヘリウムの観測は，電子観測とは異なりよりシミュレーションに対する依存性が強く難しい解析となる．その意味で，ヘリウム，炭素，酸素を含む核子成分のビームテスト結果の解析を含み，シミュレーションの検証や詳細な系統誤差の評価を加えた炭素・酸素論文を出版できたことは，ヘリウムの解析結果出版に向けても大きな成果と言える．
陽子・ヘリウムデータ解析においては，特に最大の目的となる，100TeV領域における陽子ヘリウムスペクトルの冪形状を精度よく求めるため，イベント選別の信頼性，飛跡再構成方法の信頼性，モンテカルロモデル依存性，検出器内での相互作用位置の影響など，様々な系統的調査を実施した．

Research Progress Status

令和2年度が最終年度であるため、記入しない。

Strategy for Future Research Activity

令和2年度が最終年度であるため、記入しない。

Research Products

• [Int'l Joint Research] Pisa University & INFN/Florence University & INFN/IFAC-CNR(イタリア)
• [Int'l Joint Research] NASA Goddard Space Flight Center/Louisiana State University/Washington University St. Louis(米国)
• [Int'l Joint Research] Pisa University and INFN/Florence University and INFN/IFAC-CNR(イタリア)
• [Int'l Joint Research] NASA Goddard Space Flight Center/Louisiana State University/Washington University St. Louis(米国)
• [Journal Article] Direct Measurement of the Cosmic-Ray Carbon and Oxygen Spectra from 10??GeV/n to 2.2??TeV/n with the Calorimetric Electron Telescope on the International Space Station (2020)
  • Author(s): Adriani O.、Akaike Y.、Asano K.、Asaoka Y.、Bagliesi M.G.、Berti E.、Bigongiari G.、Binns W.R.、Bongi M.、Brogi P.、Bruno A.、Buckley J.H.、Cannady N.、Castellini G.、Checchia C.、Cherry M.L.、Collazuol G.、Ebisawa K.、Fuke H.、Gonzi S.、Guzik T.G.、Hams T.、Hibino K.、Ichimura M. 他
  • Journal Title: Physical Review Letters Volume: 125 Issue: 25 Pages: 251102-251102
  • DOI: 10.1103/physrevlett.125.251102
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Direct Measurement of the Cosmic-Ray Proton Spectrum from 50 GeV to 10 TeV with the Calorimetric Electron Telescope on the International Space Station (2019)
  • Author(s): O,Adriani, Y.Asaoka, M.Mori, S.Torii et al. (CALET Collaboration)
  • Journal Title: Physical Review Letters Volume: 122 Issue: 18 Pages: 181102-181102
  • DOI: 10.1103/physrevlett.122.181102
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Measurements of Heavy Cosmic-Ray Nuclei Spectra with CALET on the ISS (2019)
  • Author(s): Y.Akaike et al. (CALET Collaboration)
  • Journal Title: Journal of Physics: Conf. Series (26th Extended European Cosmic Ray Symposium) Volume: 1181 Pages: 012042-012042
  • DOI: 10.1088/1742-6596/1181/1/012042
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] The CALorimetric Electron Telescope (CALET) on the International Space Station: Results from the First Two Years (2019)
  • Author(s): Y Asaoka et al. (CALET Collaboration)
  • Journal Title: Journal of Physics: Conf. Series (26th Extended European Cosmic Ray Symposium) Volume: 1181 Pages: 012003-012003
  • DOI: 10.1088/1742-6596/1181/1/012003
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] The CALorimetric Electron Telescope (CALET) on the International Space Station (2019)
  • Author(s): Shoji Torii and Pier Simone Marrocchesi for the CALET collaboration
  • Journal Title: Advances in Space Research Volume: 64 Issue: 12 Pages: 2531-2537
  • DOI: 10.1016/j.asr.2019.04.013
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Measurement of cosmic-ray carbon and oxygen energy spectra with CALET (2019)
  • Author(s): Paolo Maestro for the CALET collaboration
  • Journal Title: Advances in Space Research Volume: 64 Issue: 12 Pages: 2538-2545
  • DOI: 10.1016/j.asr.2019.04.015
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] The CALorimetric Electron Telescope (CALET) on the International Space Station: Results from the First Two Years of Operation (2019)
  • Author(s): Asaoka Y、et al
  • Journal Title: EPJ Web of Conferences Volume: 208 Pages: 13001-13001
  • DOI: 10.1051/epjconf/201920813001
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Radiation dose during relativistic electron precipitation events at the International Space Station (2019)
  • Author(s): Ueno H., Nakahira S., Kataoka R., Asaoka Y., Torii S., Ozawa S., Matsumoto H., Bruno A., Nolfo G.A., Collazuol G., Ricciarini S.B.
  • Journal Title: Space Weather Volume: - Issue: 7 Pages: 209431-7
  • DOI: 10.1029/2019sw002280
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] An Interpretation of the Cosmic Ray Electron + Positron Spectrum from 10 GeV to 3 TeV Measured by CALET on the ISS (2019)
  • Author(s): Saptashwa Bhattacharyya, Holger Motz, Yoichi Asaoka, Shoji Torii
  • Journal Title: International Journal of Modern Physics D Volume: 28 Issue: 02 Pages: 1950035-1950035
  • DOI: 10.1142/s0218271819500354
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] The CALorimetric Electron Telescope (CALET) on the International Space Station (2019)
  • Author(s): Y. Asaoka et al. (CALET Collaboration)
  • Journal Title: Proceedings of Science (ICRC2019) Volume: 358 Pages: 0011-16
  • Open Access / Int'l Joint Research
• [Journal Article] Measurements of Heavy Cosmic Ray Nuclei Fluxes with CALET (2019)
  • Author(s): Y.Akaike et al. (CALET Collaboration)
  • Journal Title: Proceedings of Science (ICRC2019) Volume: 358 Pages: 0341-8
  • Open Access / Int'l Joint Research
• [Journal Article] Measurement of the Proton Spectrum with CALET on the ISS (2019)
  • Author(s): P.S.Morrocchesi et al. (CALET Collaboration)
  • Journal Title: Proceedings of Science (ICRC2019) Volume: 358 Pages: 1031-8
  • Open Access / Int'l Joint Research
• [Journal Article] Analysis of CALET Data for Anisotropy in Electron+Positron Cosmic Rays (2019)
  • Author(s): H.Motz and Y.Asaoka (CALET Collaboration)
  • Journal Title: Proceeding of Science (ICRC2019) Volume: 358 Pages: 1121-8
  • Open Access / Int'l Joint Research
• [Journal Article] CALET Ultra Heavy Cosmic Ray Observations on the ISS (2019)
  • Author(s): B. F. Rauch, W. Binns et al. (CALET Collaboration)
  • Journal Title: Proceeding of Science (ICRC2019) Volume: 358 Pages: 1301-8
  • Open Access / Int'l Joint Research
• [Journal Article] Extended Measurement of Cosmic-Ray Electron and Positron Spectrum from CALET on the ISS (2019)
  • Author(s): S.Torii et al. (CALET Collaboration)
  • Journal Title: Proceeding of Science (ICRC2019) Volume: 358 Pages: 1421-8
  • Open Access / Int'l Joint Research
• [Journal Article] Interpretation of the CALET Electron+Positron Spectrum concerning Dark Matter Signatures (2019)
  • Author(s): H. Motz, Y. Asaoka and S. Bhattacharyya
  • Journal Title: Proceeding of Science (ICRC2019) Volume: 358 Pages: 5331-8
  • Open Access / Int'l Joint Research
• [Presentation] CALETによる10GeV/nから2.2TeV/nの炭素と酸素のエネルギースクトル観測結果 (2021)
  • Author(s): 赤池陽水
  • Organizer: 日本物理学会第76回年次大会
• [Presentation] CALETによる5年間の観測の進展と運用の報告 (2021)
  • Author(s): 田村忠久
  • Organizer: 日本物理学会第76回年次大会
• [Presentation] CALETによる5年間の軌道上観測の成果と展望 (2021)
  • Author(s): 鳥居祥二
  • Organizer: 日本物理学会第76回年次大会
• [Presentation] CALORIMETRIC ELECTRON TELESCOPE (CALET) ON THE INTERNATIONAL SPACE STATION (2021)
  • Author(s): Shoji Torii
  • Organizer: 43rd COSPAR Scientific Assembly (online)
  • Int'l Joint Research / Invited
• [Presentation] CALETによる宇宙線原子核のエネルギースペクトルの観測 (2021)
  • Author(s): 赤池陽水
  • Organizer: 第21回宇宙科学シンポジウム（オンライン開催）
• [Presentation] CALETによる5年間の観測の進展状況と運用の概要 (2021)
  • Author(s): 田村忠久
  • Organizer: 第21回宇宙科学シンポジウム（オンライン開催）
• [Presentation] 国際宇宙ステーション搭載CALETによる５年間観測の成果 (2021)
  • Author(s): 鳥居祥二
  • Organizer: 第21回宇宙科学シンポジウム（オンライン開催）
• [Presentation] CALETによる4.5年間の軌道上観測の最新成果 (2020)
  • Author(s): 鳥居祥二
  • Organizer: 日本物理学会第75回年次大会（2020) オンライン
• [Presentation] CALET：4年半にわたる軌道上運用のまとめ (2020)
  • Author(s): 浅岡陽一
  • Organizer: 日本物理学会第75回年次大会（2020) オンライン
• [Presentation] CALETによる原子核エネルギースペクトルの観測 (2020)
  • Author(s): 赤池陽水
  • Organizer: 日本物理学会第75回年次大会（2020) オンライン
• [Presentation] 国際宇宙ステーション搭載CALETの最新成果 (2020)
  • Author(s): 鳥居祥二
  • Organizer: 第20回宇宙科学シンポジウム, 宇宙科学研究所, 相模原
• [Presentation] CALETの運用状況と電子、陽子・原子核スペクトル (2020)
  • Author(s): 浅岡陽一
  • Organizer: 第20回宇宙科学シンポジウム, 宇宙科学研究所, 相模原
• [Presentation] High Energy Gamma-rays and Gamma-ray Bursts Observations by CALET (2020)
  • Author(s): T. Sakamoto
  • Organizer: 第20回宇宙科学シンポジウム, 宇宙科学研究所, 相模原
• [Presentation] CALET: Calorimetric Electron Telescope (2019)
  • Author(s): Pier Simone Marrocchesi
  • Organizer: XSCRC2019: Cross sections for Cosmic Rays, CERN, Geneva, Switzerland
  • Int'l Joint Research / Invited
• [Presentation] Recent Results and Dark Matter Search with CALET on the ISS (2019)
  • Author(s): Yoichi Asaoka
  • Organizer: Dark Matter searches in the 2020s - At the crossroads of the WIMP, ICRR, University of Tokyo, Kashiwa, Japan
  • Int'l Joint Research / Invited
• [Presentation] CALET Results after Three Years on the International Space Station (2019)
  • Author(s): Yoichi Asaoka
  • Organizer: 16th International Conference on Topics in Astroparticle and Underground Physics, Toyama, Japan
  • Int'l Joint Research
• [Presentation] Calorimetric Electron Telescope on the International Space Station (2019)
  • Author(s): Shoji Torii
  • Organizer: Calorimetry for the High Energy Frontier: CHEF2019, Kyushu Univ. Fukuoka, Japan
  • Int'l Joint Research / Invited
• [Presentation] CALET on the International Space Station: the First Three Years of Operations (2019)
  • Author(s): Paolo Brogi
  • Organizer: 8th International Conference on New Frontiers in Physics (ICNFP2019), Crete, Greece
  • Int'l Joint Research
• [Presentation] The CALorimetric Electron Telescope (CALET) on the International Space Station (2019)
  • Author(s): Yoichi Asaoka
  • Organizer: ICRC2019: 36th International Cosmic Ray Conference, Madison, WI, USA
  • Int'l Joint Research / Invited
• [Presentation] Interpretation of the CALET Electron+Positron Spectrum concerning Dark Matter Signatures (2019)
  • Author(s): Holger Motz
  • Organizer: ICRC2019: 36th International Cosmic Ray Conference, Madison, WI, USA
  • Int'l Joint Research
• [Presentation] Measurements of Heavy Cosmic Ray Nuclei Fluxes with CALET (2019)
  • Author(s): Yosui Akaike
  • Organizer: ICRC2019: 36th International Cosmic Ray Conference, Madison, WI, USA
  • Int'l Joint Research
• [Presentation] Measurement of the Proton Spectrum with CALET on the ISS (2019)
  • Author(s): Pier Simone Marrocchesi
  • Organizer: ICRC2019: 36th International Cosmic Ray Conference, Madison, WI, USA
  • Int'l Joint Research
• [Presentation] Analysis of CALET Data for Anisotropy in Electron+Positron Cosmic Rays (2019)
  • Author(s): Holger Motz
  • Organizer: ICRC2019: 36th International Cosmic Ray Conference, Madison, WI, USA
  • Int'l Joint Research
• [Presentation] CALET Ultra Heavy Cosmic Ray Observations on the ISS (2019)
  • Author(s): Brian F. Rauch
  • Organizer: ICRC2019: 36th International Cosmic Ray Conference, Madison, WI, USA
  • Int'l Joint Research
• [Presentation] Extended Measurement of Cosmic-Ray Electron and Positron Spectrum from CALET on the ISS (2019)
  • Author(s): Shoji Torii
  • Organizer: ICRC2019: 36th International Cosmic Ray Conference, Madison, WI, USA
  • Int'l Joint Research
• [Presentation] An Overview of CALET Observations after 3 Years on ISS (2019)
  • Author(s): Pier Simone Marrocchesi
  • Organizer: EPS-HEP2019: European Physical Society Conference on High Energy Physics, Ghent, Belgium
  • Int'l Joint Research
• [Presentation] CALET Results after Three Years on Orbit on the International Space Station (2019)
  • Author(s): Paolo Maestro
  • Organizer: ISCRA2019: International Sympsium on Cosmic Rays and Astrophysics, MEPhI, Moscow, Russia
• [Presentation] Calorimetric Electron Telescope (2019)
  • Author(s): Pier Simone Marrocchesi
  • Organizer: Next Generation of Astroparticle Experiments in Space (NextGapes-2019) , Moscow, Russia
  • Int'l Joint Research / Invited
• [Presentation] CALETによる軌道上観測の最新成果 (2019)
  • Author(s): 鳥居祥二
  • Organizer: 日本物理学会2019年秋季大会 山形大学
• [Presentation] CALETによる宇宙線直接観測：陽子スペクトルの漸次的な硬化の高精度検出 (2019)
  • Author(s): 浅岡陽一
  • Organizer: 日本物理学会2019年秋季大会 山形大学
• [Presentation] CALETによる炭素と酸素のエネルギースペクトル測定 (2019)
  • Author(s): 赤池陽水
  • Organizer: 日本物理学会2019年秋季大会 山形大学
• [Presentation] Search for Anisotropy in Electron+Positron Cosmic Rays using CALET Data (2019)
  • Author(s): Holger Motz
  • Organizer: 日本物理学会2019年秋季大会 山形大学
• [Presentation] 宇宙線直接観測と暗黒物質の間接探索 (2019)
  • Author(s): 浅岡陽一
  • Organizer: ダークマターの懇談会 早稲田大学
  • Invited
• [Remarks] CALET-カロリメータ型宇宙電子線望遠鏡
  • URL: https://calet.jp
• [Remarks] DARTS/CALET at ISAS/JAXA
  • URL: http://darts.jaxa.jp/astro/calet
• [Remarks] 高エネルギー電子・ガンマ線観測装置（CALET)
  • URL: https://iss.jaxa.jp/kiboexp/equipment/ef/calet