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Direct evidence of nonstationary collisionless shocks in space plasmas
Collisionless shocks are ubiquitous throughout the universe: around stars, supernova remnants, active galactic nuclei, binary systems, comets, and planets. Key information is carried by electromagnetic emissions from particles accelerated by high Mach number collisionless shocks. These shocks are in...
Autores principales: | , , , , , , , , , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
American Association for the Advancement of Science
2019
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6392793/ https://www.ncbi.nlm.nih.gov/pubmed/30820454 http://dx.doi.org/10.1126/sciadv.aau9926 |
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author | Dimmock, Andrew P. Russell, Christopher T. Sagdeev, Roald Z. Krasnoselskikh, Vladimir Walker, Simon N. Carr, Christopher Dandouras, Iannis Escoubet, C. Philippe Ganushkina, Natalia Gedalin, Michael Khotyaintsev, Yuri V. Aryan, Homayon Pulkkinen, Tuija I. Balikhin, Michael A. |
author_facet | Dimmock, Andrew P. Russell, Christopher T. Sagdeev, Roald Z. Krasnoselskikh, Vladimir Walker, Simon N. Carr, Christopher Dandouras, Iannis Escoubet, C. Philippe Ganushkina, Natalia Gedalin, Michael Khotyaintsev, Yuri V. Aryan, Homayon Pulkkinen, Tuija I. Balikhin, Michael A. |
author_sort | Dimmock, Andrew P. |
collection | PubMed |
description | Collisionless shocks are ubiquitous throughout the universe: around stars, supernova remnants, active galactic nuclei, binary systems, comets, and planets. Key information is carried by electromagnetic emissions from particles accelerated by high Mach number collisionless shocks. These shocks are intrinsically nonstationary, and the characteristic physical scales responsible for particle acceleration remain unknown. Quantifying these scales is crucial, as it affects the fundamental process of redistributing upstream plasma kinetic energy into other degrees of freedom—particularly electron thermalization. Direct in situ measurements of nonstationary shock dynamics have not been reported. Thus, the model that best describes this process has remained unknown. Here, we present direct evidence demonstrating that the transition to nonstationarity is associated with electron-scale field structures inside the shock ramp. |
format | Online Article Text |
id | pubmed-6392793 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2019 |
publisher | American Association for the Advancement of Science |
record_format | MEDLINE/PubMed |
spelling | pubmed-63927932019-02-28 Direct evidence of nonstationary collisionless shocks in space plasmas Dimmock, Andrew P. Russell, Christopher T. Sagdeev, Roald Z. Krasnoselskikh, Vladimir Walker, Simon N. Carr, Christopher Dandouras, Iannis Escoubet, C. Philippe Ganushkina, Natalia Gedalin, Michael Khotyaintsev, Yuri V. Aryan, Homayon Pulkkinen, Tuija I. Balikhin, Michael A. Sci Adv Research Articles Collisionless shocks are ubiquitous throughout the universe: around stars, supernova remnants, active galactic nuclei, binary systems, comets, and planets. Key information is carried by electromagnetic emissions from particles accelerated by high Mach number collisionless shocks. These shocks are intrinsically nonstationary, and the characteristic physical scales responsible for particle acceleration remain unknown. Quantifying these scales is crucial, as it affects the fundamental process of redistributing upstream plasma kinetic energy into other degrees of freedom—particularly electron thermalization. Direct in situ measurements of nonstationary shock dynamics have not been reported. Thus, the model that best describes this process has remained unknown. Here, we present direct evidence demonstrating that the transition to nonstationarity is associated with electron-scale field structures inside the shock ramp. American Association for the Advancement of Science 2019-02-27 /pmc/articles/PMC6392793/ /pubmed/30820454 http://dx.doi.org/10.1126/sciadv.aau9926 Text en Copyright © 2019 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works. Distributed under a Creative Commons Attribution License 4.0 (CC BY). http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution license (http://creativecommons.org/licenses/by/4.0/) , which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. |
spellingShingle | Research Articles Dimmock, Andrew P. Russell, Christopher T. Sagdeev, Roald Z. Krasnoselskikh, Vladimir Walker, Simon N. Carr, Christopher Dandouras, Iannis Escoubet, C. Philippe Ganushkina, Natalia Gedalin, Michael Khotyaintsev, Yuri V. Aryan, Homayon Pulkkinen, Tuija I. Balikhin, Michael A. Direct evidence of nonstationary collisionless shocks in space plasmas |
title | Direct evidence of nonstationary collisionless shocks in space plasmas |
title_full | Direct evidence of nonstationary collisionless shocks in space plasmas |
title_fullStr | Direct evidence of nonstationary collisionless shocks in space plasmas |
title_full_unstemmed | Direct evidence of nonstationary collisionless shocks in space plasmas |
title_short | Direct evidence of nonstationary collisionless shocks in space plasmas |
title_sort | direct evidence of nonstationary collisionless shocks in space plasmas |
topic | Research Articles |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6392793/ https://www.ncbi.nlm.nih.gov/pubmed/30820454 http://dx.doi.org/10.1126/sciadv.aau9926 |
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