Academic Journal

Electron Acceleration by Multiple Fast Fermi Reflections at Earth’s Bow Shock

التفاصيل البيبلوغرافية
العنوان: Electron Acceleration by Multiple Fast Fermi Reflections at Earth’s Bow Shock
المؤلفون: Y. Y. Liu, J. B. Cao, C. M. Liu, Y. T. Song, D. K. Hu
المصدر: The Astrophysical Journal, Vol 979, Iss 2, p 179 (2025)
بيانات النشر: IOP Publishing, 2025.
سنة النشر: 2025
المجموعة: LCC:Astrophysics
مصطلحات موضوعية: Interplanetary particle acceleration, Planetary bow shocks, Shocks, Solar wind, Astrophysics, QB460-466
الوصف: The generation of energetic particles in the Universe is an important topic in astrophysical and space physics. Although the diffusive shock acceleration has been acknowledged to play an essential role in particle acceleration, the injection problem has not been well resolved yet. Using measurements from the Magnetospheric Multiscale spacecraft, we report unexpected spiky enhancements of energetic electron flux in the upstream region of the Earth’s bow shock. Such enhancements are then demonstrated to result from the accelerated electron population by shock reflection. Meanwhile, the magnetic field exhibits no variations except an increase in radius of curvature. Based on the results above, we uncover the underlying acceleration scenario. When the interplanetary magnetic field with a proper curvature approaches the bow shock, the two ends of a magnetic field line may touch the shock front earlier than its middle part. Magnetic mirror points form at the two field-line-shock intersections. The solar wind electrons are therefore trapped and bounce between two mirror points. Eventually, these electrons undergo fast Fermi reflection several times and gain substantial energies. The spacecraft observation of accelerated electrons is reproduced with a numerical method based on the reflection model. Such an acceleration process may be a potential solution to the injection problem.
نوع الوثيقة: article
وصف الملف: electronic resource
اللغة: English
تدمد: 1538-4357
Relation: https://doaj.org/toc/1538-4357
DOI: 10.3847/1538-4357/ada5f0
URL الوصول: https://doaj.org/article/913d778bedfa48ffb557f40c7093911d
رقم الانضمام: edsdoj.913d778bedfa48ffb557f40c7093911d
قاعدة البيانات: Directory of Open Access Journals
الوصف
تدمد:15384357
DOI:10.3847/1538-4357/ada5f0