The Energy Spectrum of the Solar Wind Core
Abstract
The solar wind electron distribution is typically characterised as having three components, a broadly isotropic core at the lowest energies, an isotropic halo at higher energies and a field-aligned strahl at energies similar to those of the halo. Historically, the core has been described by a Maxwellian distribution function while the halo and strahl are known to be suprathermal and have been described using kappa functions. We use high energy resolution Cluster PEACE measurements to re-examine the spectral shape of the observed distributions at core energies and find that, at least some of the time, a kappa function better describes them than a Maxwellian. During these times, no spectral break is found at typical halo energies. We discuss the causes and implications of this in the context of Solar Orbiter and Parker Solar Probe.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2017
- Bibcode:
- 2017AGUFMSH23D2685W
- Keywords:
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- 7509 Corona;
- SOLAR PHYSICS;
- ASTROPHYSICS;
- AND ASTRONOMY;
- 7513 Coronal mass ejections;
- SOLAR PHYSICS;
- ASTROPHYSICS;
- AND ASTRONOMY;
- 7514 Energetic particles;
- SOLAR PHYSICS;
- ASTROPHYSICS;
- AND ASTRONOMY;
- 7845 Particle acceleration;
- SPACE PLASMA PHYSICS