Acceleration of electrons and ions by an "almost" astrophysical shock in the heliosphere

Immanuel Christopher Jebaraj; Oleksiy Agapitov; Vladimir Krasnoselskikh; Laura Vuorinen; Michael Gedalin; Kyung-Eun Choi; Erika Palmerio; Nina Dresing; Christina Cohen; Michael Balikhin; Athanasios Kouloumvakos; Nicolas Wijsen; Rami Vainio; Emilia Kilpua; Alexandr Afanasiev; Jaye Verniero; John Grant Mitchell; Domenico Trotta; Matthew Hill; Nour Raouafi; Stuart D. Bale

arXiv · 2405.07074

Acceleration of electrons and ions by an "almost" astrophysical shock in the heliosphere

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Abstract

Collisionless shock waves, ubiquitous in the universe, are crucial for particle acceleration in various astrophysical systems. Currently, the heliosphere is the only natural environment available for their in situ study. In this work, we showcase the collective acceleration of electrons and ions by one of the fastest in situ shocks ever recorded, observed by the pioneering Parker Solar Probe at only 34.5 million kilometers from the Sun. Our analysis of this unprecedented, near-parallel shock shows electron acceleration up to 6 MeV amidst intense multi-scale electromagnetic wave emissions. We also present evidence of a variable shock structure capable of injecting and accelerating ions from the solar wind to high energies through a self-consistent process. The exceptional capability of the probe's instruments to measure electromagnetic fields in a shock traveling at 1% the speed of light has enabled us, for the first time, to confirm that the structure of a strong heliospheric shock aligns with theoretical models of strong shocks observed in astrophysical environments. This alignment offers viable avenues for understanding astrophysical shock processes and the acceleration of charged particles.

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Immanuel Christopher Jebaraj, Oleksiy Agapitov, Vladimir Krasnoselskikh, Laura Vuorinen, Michael Gedalin, Kyung-Eun Choi, Erika Palmerio, Nina Dresing, Christina Cohen, Michael Balikhin, Athanasios Kouloumvakos, Nicolas Wijsen, Rami Vainio, Emilia Kilpua, Alexandr Afanasiev, Jaye Verniero, John Grant Mitchell, Domenico Trotta, Matthew Hill, Nour Raouafi, Stuart D. Bale. 2024-05-11. Acceleration of electrons and ions by an "almost" astrophysical shock in the heliosphere. https://arxiv.org/abs/2405.07074

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