Parker Solar Probe evidence for scattering of electrons in the young solar wind by narrowband whistler-mode waves
| Autor: | John Wygant, Jasper Halekas, Stuart D. Bale, P. Whittesley, J. Dombeck, Aaron Breneman, Michael L. Stevens, Katherine Goodrich, Cynthia A Cattell, Justin C. Kasper, T. Dudok de Wit, Michel Moncuquet, David M. Malaspina, Robert J. MacDowall, Marc Pulupa, B. Short, T. Case, Davin Larson |
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| Přispěvatelé: | University of Minnesota [Twin Cities] (UMN), University of Minnesota System, Space Sciences Laboratory [Berkeley] (SSL), University of California [Berkeley], University of California-University of California, Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Observatoire de Paris, Université Paris sciences et lettres (PSL) |
| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
010504 meteorology & atmospheric sciences
Whistler FOS: Physical sciences Electron 01 natural sciences 7. Clean energy Physics - Space Physics 0103 physical sciences Pitch angle 010303 astronomy & astrophysics Solar and Stellar Astrophysics (astro-ph.SR) 0105 earth and related environmental sciences Physics Scattering Astronomy and Astrophysics Space Physics (physics.space-ph) Physics - Plasma Physics Computational physics Plasma Physics (physics.plasm-ph) Strahl Solar wind Amplitude Astrophysics - Solar and Stellar Astrophysics Space and Planetary Science [SDU]Sciences of the Universe [physics] Physics::Space Physics Electron scattering |
| Zdroj: | The Astrophysical journal letters The Astrophysical journal letters, Bristol : IOP Publishing, 2021, 911 (2), pp.L29. ⟨10.3847/2041-8213/abefdd⟩ |
| ISSN: | 2041-8205 2041-8213 |
| DOI: | 10.3847/2041-8213/abefdd⟩ |
| Popis: | Observations of plasma waves by the Fields Suite and of electrons by the Solar Wind Electrons Alphas and Protons Investigation (SWEAP) on Parker Solar Probe provide strong evidence for pitch angle scattering of strahl-energy electrons by narrowband whistler-mode waves at radial distances less than ~0.3 AU. We present two example intervals of a few hours that include 8 waveform captures with whistler-mode waves and 26 representative electron distributions that are examined in detail. Two were narrow; 17 were clearly broadened, and 8 were very broad. The two with narrow strahl occurred when there were either no whistlers or very intermittent low amplitude waves. Six of the eight broadest distributions were associated with intense, long duration waves. Approximately half of the observed electron distributions have features consistent with an energy dependent scattering mechanism, as would be expected from interactions with narrowband waves. A comparison of the wave power in the whistler-mode frequency band to pitch angle width and a measure of anisotropy provides additional evidence for the electron scattering by whistler-mode waves. The pitch angle broadening occurs in over an energy range comparable to that obtained for the n=1 (co-streaming) resonance for the observed wave and plasma parameters. The additional observation that the heat flux is lower in the interval with multiple switchbacks may provide clues to the nature of switchbacks. These results provide strong evidence that the heat flux is reduced by narroweband whistler-mode waves scattering of strahl-energy electrons. 19 pages, 4 figures, 1 table |
| Databáze: | OpenAIRE |
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