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| Titel |
Additional acceleration of solar-wind particles in current sheets of the heliosphere |
| VerfasserIn |
V. Zharkova, O. Khabarova |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
0992-7689
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| Digitales Dokument |
URL |
| Erschienen |
In: Annales Geophysicae ; 33, no. 4 ; Nr. 33, no. 4 (2015-04-09), S.457-470 |
| Datensatznummer |
250121188
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| Publikation (Nr.) |
 copernicus.org/angeo-33-457-2015.pdf |
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| Zusammenfassung |
| Particles of fast solar wind in the vicinity of the heliospheric current sheet
(HCS) or in a front of interplanetary coronal mass ejections (ICMEs) often
reveal very peculiar energy or velocity profiles, density distributions with
double or triple peaks, and well-defined streams of electrons occurring around
or far away from these events. In order to interpret the parameters of
energetic particles (both ions and electrons) measured by the WIND
spacecraft during the HCS crossings, a comparison of the data was carried out with 3-D
particle-in-cell (PIC) simulations for the relevant magnetic topology
(Zharkova and Khabarova, 2012). The simulations showed that all the observed particle-energy
distributions, densities, ion peak velocities, electron pitch angles and
directivities can be fitted with the same model if the heliospheric current
sheet is in a status of continuous magnetic reconnection. In this paper we
present further observations of the solar-wind particles being accelerated to
rather higher energies while passing through the HCS and the evidence that
this acceleration happens well before the appearance of the corotating
interacting region (CIR), which passes through the spacecraft position hours
later. We show that the measured particle characteristics (ion velocity,
electron pitch angles and the distance at which electrons are turned from the
HCS) are in agreement with the simulations of additional particle
acceleration in a reconnecting HCS with a strong guiding field as measured by
WIND. A few examples are also presented showing additional acceleration of
solar-wind particles during their passage through current sheets formed in a
front of ICMEs. This additional acceleration at the ICME current sheets can
explain the anticorrelation of ion and electron fluxes frequently observed
around the ICME's leading front. Furthermore, it may provide a plausible
explanation of the appearance of bidirectional "strahls" (field-aligned most
energetic suprathermal electrons) at the leading edge of ICMEs as energetic
electrons generated during a magnetic reconnection at the ICME-front current
sheet. |
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