TY  - JOUR
A1  - Vafin, Sergei
A1  - Lazar, M.
A1  - Fichtner, H.
A1  - Schlickeiser, R.
A1  - Drillisch, M.
T1  - Solar wind temperature anisotropy constraints from streaming instabilities
JF  - Astronomy and astrophysics : an international weekly journal
N2  - 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 high beta(parallel to) > 1 plasmas, and cannot explain the other limits of the temperature anisotropy reported by observations in the low beta beta(parallel to) < 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.
KW  - solar wind
KW  - instabilities
KW  - waves
KW  - turbulence
Y1  - 2018
U6  - https://doi.org/10.1051/0004-6361/201731852
SN  - 1432-0746
VL  - 613
PB  - EDP Sciences
CY  - Les Ulis
ER  -