Establishing Theory of Electron Acceleration at Shocks Based on In-situ Observation

• Project/Area Number: 17H02966
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Space and upper atmospheric physics
• Research Institution: The University of Tokyo
• Principal Investigator: Amano Takanobu 東京大学, 大学院理学系研究科(理学部), 准教授 (00514853)
• Co-Investigator(Kenkyū-buntansha): 松清 修一 九州大学, 総合理工学研究院, 准教授 (00380709)
• Project Period (FY): 2017-04-01 – 2021-03-31
• Project Status: Completed (Fiscal Year 2021)
• Budget Amount: ¥17,550,000 (Direct Cost: ¥13,500,000、Indirect Cost: ¥4,050,000); Fiscal Year 2020: ¥3,640,000 (Direct Cost: ¥2,800,000、Indirect Cost: ¥840,000); Fiscal Year 2019: ¥3,640,000 (Direct Cost: ¥2,800,000、Indirect Cost: ¥840,000); Fiscal Year 2018: ¥3,640,000 (Direct Cost: ¥2,800,000、Indirect Cost: ¥840,000); Fiscal Year 2017: ¥6,630,000 (Direct Cost: ¥5,100,000、Indirect Cost: ¥1,530,000)
• Keywords: プラズマ / 粒子加速 / 衝撃波 / プラズマ波動 / 宇宙線 / 数値シミュレーション

Outline of Final Research Achievements

The efficiency of electron acceleration at shocks in space was investigated by combining theory, observational data analysis, as well as numerical simulations. A new theoretical model for acceleration of sub-relativistic electrons was proposed, which explains spacecraft observations of Earth’s bow shock. First-principles numerical simulations have also been conducted to investigate the effect of non-stationarity and survey the parameter dependence for application to shocks in various space environments. Judging from the obtained results, the model proposed in this research may be considered as the most promising candidate to resolve the long-standing issue of electron injection in the shock acceleration theory.

Academic Significance and Societal Importance of the Research Achievements

高エネルギー粒子の加速は宇宙において普遍的に見られる現象であり，一部の粒子のみが熱的エネルギーよりも遥かに高いエネルギーまで加速されることが知られている．熱平衡状態から大きく逸脱した粒子を生成する機構として，最も有力視されているのが衝撃波における粒子加速機構である．本研究によって衝撃波粒子加速における最大の困難であった電子注入問題の解決に向けて大きな一歩を踏み出すことができた

Research Products

• [Journal Article] Critical comparison of collisionless fluid models: Nonlinear simulations of parallel firehose instability (2022)
  • Author(s): Jikei Taiki、Amano Takanobu
  • Journal Title: Physics of Plasmas Volume: 29 Issue: 2 Pages: 022102-022102
  • DOI: 10.1063/5.0077064
  • Peer Reviewed
• [Journal Article] Particle Acceleration by Pickup Process Upstream of Relativistic Shocks (2022)
  • Author(s): Iwamoto Masanori、Amano Takanobu、Matsumoto Yosuke、Matsukiyo Shuichi、Hoshino Masahiro
  • Journal Title: The Astrophysical Journal Volume: 924 Issue: 2 Pages: 108-108
  • DOI: 10.3847/1538-4357/ac38aa
  • Peer Reviewed / Open Access
• [Journal Article] Theory of Electron Injection at Oblique Shock of Finite Thickness (2022)
  • Author(s): Amano Takanobu、Hoshino Masahiro
  • Journal Title: The Astrophysical Journal Volume: 927 Issue: 1 Pages: 132-132
  • DOI: 10.3847/1538-4357/ac4f49
  • Peer Reviewed / Open Access
• [Journal Article] Preferential Energization of Lower‐Charge‐State Heavier Ions in the Near‐Earth Magnetotail (2022)
  • Author(s): Keika K.、Kasahara S.、Yokota S.、Hoshino M.、Seki K.、Amano T.、Kistler L. M.、Nos? M.、Miyoshi Y.、Hori T.、Shinohara I.
  • Journal Title: Journal of Geophysical Research: Space Physics Volume: 127 Issue: 1 Pages: 1-20
  • DOI: 10.1029/2021ja029786
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Electron Acceleration at Rippled Low-mach-number Shocks in High-beta Collisionless Cosmic Plasmas (2021)
  • Author(s): Kobzar Oleh、Niemiec Jacek、Amano Takanobu、Hoshino Masahiro、Matsukiyo Shuichi、Matsumoto Yosuke、Pohl Martin
  • Journal Title: The Astrophysical Journal Volume: 919 Issue: 2 Pages: 97-97
  • DOI: 10.3847/1538-4357/ac1107
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Mach number dependence of ion-scale kinetic instability at collisionless perpendicular shock: Condition for Weibel-dominated shock (2021)
  • Author(s): Nishigai Takuro、Amano Takanobu
  • Journal Title: Physics of Plasmas Volume: 28 Issue: 7 Pages: 072903-072903
  • DOI: 10.1063/5.0051269
  • Peer Reviewed
• [Journal Article] A non-local fluid closure for modeling cyclotron resonance in collisionless magnetized plasmas (2021)
  • Author(s): Jikei Taiki、Amano Takanobu
  • Journal Title: Physics of Plasmas Volume: 28 Issue: 4 Pages: 042105-042105
  • DOI: 10.1063/5.0045335
  • Peer Reviewed
• [Journal Article] Mildly relativistic magnetized shocks in electron-ion plasmas - II. Particle acceleration and heating (2021)
  • Author(s): Ligorini Arianna、Niemiec Jacek、Kobzar Oleh、Iwamoto Masanori、Bohdan Artem、Pohl Martin、Matsumoto Yosuke、Amano Takanobu、Matsukiyo Shuichi、Hoshino Masahiro
  • Journal Title: Monthly Notices of the Royal Astronomical Society Volume: 502 Issue: 4 Pages: 5065-5074
  • DOI: 10.1093/mnras/stab220
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Magnetic Field Amplification by the Weibel Instability at Planetary and Astrophysical Shocks with High Mach Number (2021)
  • Author(s): Bohdan Artem、Pohl Martin、Niemiec Jacek、Morris Paul J.、Matsumoto Yosuke、Amano Takanobu、Hoshino Masahiro、Sulaiman Ali
  • Journal Title: Physical Review Letters Volume: 126 Issue: 9 Pages: 095101-095101
  • DOI: 10.1103/physrevlett.126.095101
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Energy Transfer Between Hot Protons and Electromagnetic Ion Cyclotron Waves in Compressional Pc5 Ultra‐low Frequency Waves (2021)
  • Author(s): Kitamura N.、Shoji M.、Nakamura S.、Kitahara M.、Amano T.、Omura Y.、Hasegawa H.、Boardsen S. A.、Miyoshi Y.、Katoh Y.、Teramoto M.、Saito Y.、Yokota S.、Hirahara M.、Gershman D. J.、Giles B. L.、Russell C. T.、Strangeway R. J.、Ahmadi N.、Lindqvist P.‐A.、Ergun R. E.、Fuselier S. A.、Burch J. L.
  • Journal Title: Journal of Geophysical Research: Space Physics Volume: 126 Issue: 5 Pages: 1-25
  • DOI: 10.1029/2020ja028912
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Mildly relativistic magnetized shocks in electron ion plasmas: I. Electromagnetic shock structure (2020)
  • Author(s): Ligorini Arianna、Niemiec Jacek、Kobzar Oleh、Iwamoto Masanori、Bohdan Artem、Pohl Martin、Matsumoto Yosuke、Amano Takanobu、Matsukiyo Shuichi、Esaki Yodai、Hoshino Masahiro
  • Journal Title: Monthly Notices of the Royal Astronomical Society Volume: 501 Issue: 4 Pages: 4837-4849
  • DOI: 10.1093/mnras/staa3901
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Kinetic Simulations of Nonrelativistic Perpendicular Shocks of Young Supernova Remnants. III. Magnetic Reconnection (2020)
  • Author(s): Bohdan Artem、Pohl Martin、Niemiec Jacek、Vafin Sergei、Matsumoto Yosuke、Amano Takanobu、Hoshino Masahiro
  • Journal Title: The Astrophysical Journal Volume: 893 Issue: 1 Pages: 6-6
  • DOI: 10.3847/1538-4357/ab7cd6
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Observational Evidence for Stochastic Shock Drift Acceleration of Electrons at the Earth’s Bow Shock (2020)
  • Author(s): Amano T.、Katou T.、Kitamura N.、Oka M.、Matsumoto Y.、Hoshino M.、Saito Y.、Yokota S.、Giles B. L.、Paterson W.?R.、Russell C. T.、Le Contel O.、Ergun R. E.、Lindqvist P.-A.、Turner D. L.、Fennell J. F.、Blake J. B.
  • Journal Title: Physical Review Letters Volume: 124 Issue: 6 Pages: 065101-065101
  • DOI: 10.1103/physrevlett.124.065101
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Kinetic Simulations of Nonrelativistic Perpendicular Shocks of Young Supernova Remnants. I. Electron Shock-surfing Acceleration (2019)
  • Author(s): Bohdan Artem、Niemiec Jacek、Pohl Martin、Matsumoto Yosuke、Amano Takanobu、Hoshino Masahiro
  • Journal Title: The Astrophysical Journal Volume: 878 Issue: 1 Pages: 5-5
  • DOI: 10.3847/1538-4357/ab1b6d
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Electron Scattering by Low-Frequency Whistler Waves at Earth's Bow Shock (2019)
  • Author(s): M. Oka, F. Otsuka, S. Matsukiyo, L. B. Wilson III, M. R. Argall, T. Amano, T. D. Phan, M. Hoshino, O. Le Contel, D. J. Gershman, J. L. Burch, R. B. Torbert, J. C. Dorelli, B. L. Giles, R. E. Ergun, C. T. Russell, and P. A. Lindqvist
  • Journal Title: Astrophysical Journal Volume: 886 Issue: 1 Pages: 53-53
  • DOI: 10.3847/1538-4357/ab4a81
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Kinetic simulations of nonrelativistic perpendicular shocks of young supernova remnants. II. Influence of shock-surfing acceleration on downstream electron spectra (2019)
  • Author(s): Artem Bohdan, Jacek Niemiec, Martin Pohl, Yosuke Matsumoto, Takanobu Amano, and Masahiro Hoshino
  • Journal Title: Astrophysical Journal Volume: 885 Issue: 1 Pages: 10-10
  • DOI: 10.3847/1538-4357/ab43cf
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Precursor Wave Amplification by Ion?Electron Coupling through Wakefield in Relativistic Shocks (2019)
  • Author(s): Iwamoto Masanori、Amano Takanobu、Hoshino Masahiro、Matsumoto Yosuke、Niemiec Jacek、Ligorini Arianna、Kobzar Oleh、Pohl Martin
  • Journal Title: The Astrophysical Journal Volume: 883 Issue: 2 Pages: L35-L35
  • DOI: 10.3847/2041-8213/ab4265
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Excitation of storm time Pc5 ULF waves by ring current ions based on the drift‐kinetic simulation (2019)
  • Author(s): Yamakawa, T., K. Seki, T. Amano, N. Takahashi, and Y. Miyoshi
  • Journal Title: Geophys. Res. Lett. Volume: 46 Issue: 4 Pages: 1911-1918
  • DOI: 10.1029/2018gl081573
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] The Efficiency of Coherent Radiation from Relativistic Shocks (2019)
  • Author(s): Amano Takanobu、Iwamoto Masanori、Matsumoto Yosuke、Hoshino Masahiro
  • Journal Title: In: Yamanouchi K., Tunik S., Makarov V. (eds) Progress in Photon Science. Springer Series in Chemical Physics Volume: 119 Pages: 371-383
  • DOI: 10.1007/978-3-030-05974-3_19
  • ISBN: 9783030059736, 9783030059743
  • Peer Reviewed
• [Journal Article] Theory of Stochastic Shock Drift Acceleration for Electrons in the Shock Transition Region (2019)
  • Author(s): Katou Takuma、Amano Takanobu
  • Journal Title: The Astrophysical Journal Volume: 874 Issue: 2 Pages: 119-119
  • DOI: 10.3847/1538-4357/ab0d8a
  • Peer Reviewed
• [Journal Article] Ion energies dominating energy density in the inner magnetosphere: Spatial distributions and composition, observed by Arase/MEP-i (2018)
  • Author(s): Keika, K. S. Kasahara, S. Yokota, M. Hoshino, K. Seki, M. Nose, T. Amano, Y. Miyoshi, and I. Shinohara,
  • Journal Title: Geophysical Research Letters Volume: 45 Issue: 22 Pages: 12153-12162
  • DOI: 10.1029/2018gl080047
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Formation of butterfly pitch angle distributions of relativistic electrons in the outer radiation belt with a monochromatic Pc5 wave (2018)
  • Author(s): Kamiya, K., K. Seki, S. Saito, T. Amano, and Y. Miyoshi
  • Journal Title: J. Geophys. Res. Volume: 印刷中 Issue: 6 Pages: 4679-4691
  • DOI: 10.1002/2017ja024764
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] A statistical study of slow-mode shocks observed by MMS in the dayside magnetopause (2018)
  • Author(s): Walia, N. K., K. Seki, M. Hoshino, T. Amano, N. Kitamura, Y. Saito, S. Yokota, C. J. Pollock, B. L. Giles, T. E. Moore, R. B. Torbert, C. T. Russell, and J. L. Burch
  • Journal Title: Geophys. Res. Lett. Volume: 45 Issue: 10 Pages: 4675-4684
  • DOI: 10.1029/2018gl077580
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Precursor Wave Emission Enhanced by Weibel Instability in Relativistic Shocks (2018)
  • Author(s): Iwamoto Masanori、Amano Takanobu、Hoshino Masahiro、Matsumoto Yosuke
  • Journal Title: The Astrophysical Journal Volume: 858 Issue: 2 Pages: 93-93
  • DOI: 10.3847/1538-4357/aaba7a
  • Peer Reviewed
• [Journal Article] A generalized quasi-neutral fluid-particle hybrid plasma model and its application to energetic-particle-magnetohydrodynamics hybrid simulation (2018)
  • Author(s): Amano Takanobu
  • Journal Title: Journal of Computational Physics Volume: 366 Pages: 366-385
  • DOI: 10.1016/j.jcp.2018.04.020
  • Peer Reviewed
• [Journal Article] Theory, modeling, and integrated studies in the Arase (ERG) project (2018)
  • Author(s): Seki Kanako、Miyoshi Yoshizumi、Ebihara Yusuke、Katoh Yuto、Amano Takanobu、Saito Shinji、Shoji Masafumi、Nakamizo Aoi、Keika Kunihiro、Hori Tomoaki、Nakano Shin’ya、Watanabe Shigeto、Kamiya Kei、Takahashi Naoko、Omura Yoshiharu、Nose Masahito、Fok Mei-Ching、Tanaka Takashi、Ieda Akimasa、Yoshikawa Akimasa
  • Journal Title: Earth, Planets and Space Volume: 70 Issue: 1 Pages: 17-17
  • DOI: 10.1186/s40623-018-0785-9
  • NAID: 120006517789
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Electron Surfing and Drift Accelerations in a Weibel-Dominated High-Mach-Number Shock (2017)
  • Author(s): Matsumoto Yosuke、Amano Takanobu、Kato Tsunehiko N.、Hoshino Masahiro
  • Journal Title: Physical Review Letters Volume: 119 Issue: 10 Pages: 105101-105101
  • DOI: 10.1103/physrevlett.119.105101
  • NAID: 120007088133
  • Peer Reviewed
• [Journal Article] Electron Scattering by High-frequency Whistler Waves at Earth’s Bow Shock (2017)
  • Author(s): Oka M.、III L. B. Wilson、Phan T. D.、Hull A. J.、Amano T., et al. (全24名)
  • Journal Title: The Astrophysical Journal Volume: 842 Issue: 2 Pages: L11-L11
  • DOI: 10.3847/2041-8213/aa7759
  • Peer Reviewed / Int'l Joint Research
• [Presentation] Electron injection at shocks: Transition from stochastic shock drift acceleration to diffusive shock acceleration (2022)
  • Author(s): Amano, T., et al.
  • Organizer: XXVIII Cracow EPIPHANY Conference on Recent Advances in Astroparticle Physics
  • Int'l Joint Research / Invited
• [Presentation] ミクロなプラズマ素過程に基づく衝撃波粒子加速機構 (2021)
  • Author(s): 天野孝伸, 他
  • Organizer: 高エネルギー現象で探る宇宙の多様性Ⅰ
  • Invited
• [Presentation] Connecting Injection and Subsequent Acceleration of Nonthermal Electrons at Collisionless Oblique Shocks (2021)
  • Author(s): Amano, T., et al.
  • Organizer: The 30th International Toki Conference on Plasma and Fusion Research (ITC30)
  • Int'l Joint Research / Invited
• [Presentation] Stochastic Shock Drift Acceleration as the Mechanism for Electron Injection into Diffusive Shock Acceleration at Collisionless Shocks (2021)
  • Author(s): Amano, T., et al.
  • Organizer: 5th Asia-Pacific Conference on Plasma Physics (AAPPS-DPP2021)
  • Int'l Joint Research / Invited
• [Presentation] Particle Acceleration at Collisionless Shocks (2021)
  • Author(s): Amano, T.
  • Organizer: 10th East-Asia Workshop on Laboratory, Space, Astrophysical Plasmas (EASW-10)
  • Int'l Joint Research / Invited
• [Presentation] Non-thermal Particle Acceleration at Collisionless Shocks (2020)
  • Author(s): Amano, T.
  • Organizer: Max Planck Princeton Center Workshop
  • Int'l Joint Research / Invited
• [Presentation] 内部磁気圏におけるULF波動励起機構 (2019)
  • Author(s): 天野孝伸
  • Organizer: 実験室・宇宙プラズマ研究集会
  • Invited
• [Presentation] MMS observation of stochastic shock drift acceleration of electrons (2019)
  • Author(s): Amano, T., Katou, T., Kitamura, N., Oka, M., Matsumoto, Y., Hoshino, M., Saito, Y., Yokota, S., Giles, B. L., Paterson, W. R., Russel, C. T., Le Contel, O., Ergun, R. E., Lindqvist, P.-A., Turner, D. L., Fennell, J. F. Blake, J. B.
  • Organizer: GEM summer workshop 2019
  • Int'l Joint Research
• [Presentation] Observational Evidence for Stochastic Shock Drift Acceleration at Quasi-perpendicular Earth’s Bow Shock (2019)
  • Author(s): Amano, T., Katou, T., Kitamura, N., Oka, M., Matsumoto, Y., Hoshino, M., Saito, Y., Yokota, S., Giles, B. L., Paterson, W. R., Russel, C. T., Le Contel, O., Ergun, R. E., Lindqvist, P.-A., Turner, D. L., Fennell, J. F. Blake, J. B.
  • Organizer: EASW9 (9th East-Asia School and Workshop on Laboratory, Space, and Astrophysical Plasmas)
  • Int'l Joint Research
• [Presentation] Electron acceleration associated with waves in collisionless shocks (2019)
  • Author(s): Amano, T., Matsumoto, Y., Hoshino, M.
  • Organizer: 2019 URSI - Japan Radio Science Meeting
  • Int'l Joint Research
• [Presentation] MMS Observation of Stochastic Shock Drift Acceleration of Non-thermal Electron at Quasi-perpendicular Bow Shock (2019)
  • Author(s): Amano, T., Katou, T., Kitamura, N., Oka, M., Matsumoto, Y., Hoshino, M., Saito, Y., Yokota, S., Giles, B. L., Paterson, W. R., Russel, C. T., Le Contel, O., Ergun, R. E., Lindqvist, P.-A., Turner, D. L., Fennell, J. F. Blake, J. B.
  • Organizer: AGU fall meeting
  • Int'l Joint Research
• [Presentation] Cosmic-ray acceleration via astrophysical coherent radiation (2018)
  • Author(s): Amano, T., Iwamoto, M., Matsumoto, Y., Hoshino, M.
  • Organizer: ISVHECRI 2018 (20th International Symposium on Very High Energy Cosmic Ray Interactions)
  • Int'l Joint Research / Invited
• [Presentation] Stochastic Shock Drift Acceleration for Electrons (2018)
  • Author(s): Amano, T., Katou, N., Matsumoto, Y., Hoshino, M.
  • Organizer: EASW8 (8th East-Asia School and Workshop on Laboratory, Space, and Astrophysical Plasmas)
  • Int'l Joint Research / Invited
• [Presentation] Nonthermal Electron Acceleration at Earth’s Bow Shock: Theory, Simulation and Observation (2018)
  • Author(s): Amano, T., Katou, N., Kitamura, N., Matsumoto, Y., Oka, M., Hoshino, M.
  • Organizer: ISSS-13 (The 13th International School/Symposium for Space Simulations)
  • Int'l Joint Research / Invited
• [Presentation] Three-dimensional Particle-In-Cell Simulations for High Mach Number Collisionless Shocks (2018)
  • Author(s): Amano, T., Katou, N., Kitamura, N., Matsumoto, Y., Oka, M., Hoshino, M.
  • Organizer: AAPPS-DPP 2018 (2nd Asia-Pacific Conference on Plasma Physics)
  • Int'l Joint Research / Invited
• [Presentation] Prolonged Acceleration of Non-Thermal Electrons In A High Mach Number Shock Transition Region (2018)
  • Author(s): Amano, T., Matsumoto, Y., Katou, T., Hoshino, M.
  • Organizer: COSPAR 2018
  • Int'l Joint Research
• [Presentation] Particle Acceleration in Relativistic Plasmas (2018)
  • Author(s): Amano, T.
  • Organizer: Dawn of a New Era for Black Hole Jets in Active Galaxies
  • Int'l Joint Research / Invited
• [Presentation] Cosmic-Ray Acceleration via Astrophysical Coherent Radiation (2018)
  • Author(s): Amano, T.
  • Organizer: 20th International Symposium on Very High Energy Cosmic Ray Interactions (ISVHECRI)
  • Int'l Joint Research / Invited
• [Presentation] Stochastic Shock Drift Acceleration for Electrons (2018)
  • Author(s): Amano, T.
  • Organizer: 8th East-Asia Workshop on Laboratory, Space, Astrophysical Plasmas
  • Int'l Joint Research / Invited
• [Presentation] Nonthermal Electron Acceleration at Earth’s Bow Shock: Theory, Simulation and Observation (2018)
  • Author(s): Amano, T.
  • Organizer: The 13th International School/Symposium for Space Simulations (ISSS-13)
  • Int'l Joint Research / Invited
• [Presentation] Three-dimensional Particle-In-Cell Simulations for High Mach Number Collisionless Shocks (2018)
  • Author(s): Amano, T.
  • Organizer: The 2nd Asia-Pacific Conference on Plasma Physics
  • Int'l Joint Research / Invited
• [Presentation] Coherent and Stochastic Acceleration in Quasi-perpendicular Collisionless Shocks (2017)
  • Author(s): Amano, T.
  • Organizer: Workshop on Plasma Astrophysics from the Laboratory to the Non-thermal Universe
  • Int'l Joint Research / Invited
• [Presentation] Nonthermal Electrons at Quasi-perpendicular Collisionless Shocks (2017)
  • Author(s): Amano, T.
  • Organizer: 7th East-Asia Workshop on Laboratory, Space, Astrophysical Plasmas
  • Int'l Joint Research / Invited