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| Titel |
Recent Progress in Understanding the Origin and Acceleration of Suprathermal Ions and Electrons |
| VerfasserIn |
Mihir Desai, Maher Dayeh |
| Konferenz |
EGU General Assembly 2017
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 19 (2017) |
| Datensatznummer |
250139711
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| Publikation (Nr.) |
 EGU/EGU2017-3004.pdf |
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| Zusammenfassung |
| Ions and electrons with energies that lie above (i.e., ∼2 keV) that of the core or bulk solar
wind protons and electrons are known as suprathermal particles. Observations over the last
decade have shown that such suprathermal particles are an important constituent of the
overall seed population that is accelerated in solar and interplanetary events. Despite their
increased level of importance, where these populations originate from and how they are
accelerated remains highly controversial. This is partly due to the fact that these particles
exist in the so-called tail regions of the corresponding solar wind distributions where high
temporal and sensitivity measurements are sparse. Moreover, observations comprising
long-term averages (between ∼hours to more than a day) have shown conflicting results. For
instance, below ∼40 keV/nucleon the ion differential intensities in the solar wind frame
appear to exhibit a near-constant power-law spectral slope of ∼1.5, perhaps indicating a
universal acceleration mechanism. In contrast, at energies greater than ∼40 keV/nucleon, the
ion composition changes with solar activity and the energy spectra are significantly
steeper, perhaps indicating that the suprathermal pool of material also comprises
lower-energy particle populations accelerated in corotating interaction regions,
interplanetary shocks, and solar energetic particle events. This talk discusses recent
observations of suprathermal ions and electrons in terms of state-of-the-art theories and
models that have been put forward to account for their origins and acceleration. |
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