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arXiv · 2102.04328

Magnetic field amplification by the Weibel instability at planetary and astrophysical high-Mach-number shocks

Artem Bohdan·Martin Pohl·Jacek Niemiec·Paul J. Morris·Yosuke Matsumoto·Takanobu Amano·Masahiro Hoshino·Ali Sulaiman
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Abstract

Collisionless shocks are ubiquitous in the Universe and often associated with strong magnetic field. Here we use large-scale particle-in-cell simulations of non-relativistic perpendicular shocks in the high-Mach-number regime to study the amplification of magnetic field within shocks. The magnetic field is amplified at the shock transition due to the ion-ion two-stream Weibel instability. The normalized magnetic-field strength strongly correlates with the Alfv\'enic Mach number. Mock spacecraft measurements derived from PIC simulations are fully consistent with those taken in-situ at Saturn's bow shock by the Cassini spacecraft.

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Artem Bohdan, Martin Pohl, Jacek Niemiec, Paul J. Morris, Yosuke Matsumoto, Takanobu Amano, Masahiro Hoshino, Ali Sulaiman. 2021-02-08. Magnetic field amplification by the Weibel instability at planetary and astrophysical high-Mach-number shocks. https://doi.org/10.1103/physrevlett.126.095101

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