文章基本信息

标题：Solar wind temperature anisotropy constraints from streaming instabilities
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作者：S. Vafin ; M. Lazar ; H. Fichtner 等
期刊名称：Astronomy & Astrophysics
印刷版ISSN：0004-6361
电子版ISSN：1432-0746
出版年度：2018
卷号：613
DOI：10.1051/0004-6361/201731852
语种：English
出版社：EDP Sciences
摘要：Due to the relatively low rate of particle-particle collisions in the solar wind, kinetic instabilities (e.g., the mirror and firehose) play an important role in regulating large deviations from temperature isotropy. These instabilities operate in the highβ∥> 1 plasmas, and cannot explain the other limits of the temperature anisotropy reported by observations in the low betaβ∥< 1 regimes. However, the instability conditions are drastically modified in the presence of streaming (or counterstreaming) components, which are ubiquitous in space plasmas. These effects have been analyzed for the solar wind conditions in a large interval of heliospheric distances, 0.3–2.5 AU. It was found that proton counter-streams are much more crucial for plasma stability than electron ones. Moreover, new instability thresholds can potentially explain all observed bounds on the temperature anisotropy, and also the level of differential streaming in the solar wind.
关键词：Key wordsensolar windinstabilitieswavesturbulence