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| Titel |
The Helical Fields of CMEs and the Paths of Near-Relativistic Electrons into the Heliosphere |
| VerfasserIn |
D. M. Rust, D. K. Haggerty, G. Stenborg |
| Konferenz |
EGU General Assembly 2009
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 11 (2009) |
| Datensatznummer |
250024741
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| Zusammenfassung |
| Wavelet processing of the LASCO images of the solar corona brings out
many subtle details that are easily missed in the intensity images.
Specifically, wavelet processing can enhance the edges of large and
small scale structures making it easier to detect and define motions.
We used the processed LASCO images obtained during the period 1998 -
2001, of maximum activity of the last sunspot cycle, to study the
structure and motions of the CME legs and the nearby fields. Many
CMEs show large-scale latitudinal leg displacements that resemble
screw threads leaving the Sun. The helical fields extend into the
heliosphere after, and sometimes before, the associated CME has left
the LASCO C2 field of view.
We focused our attention on the CMEs that were analyzed by Simnett et
al., Ap. J. 579, 854, 2002. They linked those CMEs to beams of near-
relativistic electrons detected at 1 AU with the ACE spacecraft. Our
study shows that the electron beams\' typical delay of about 10 min in
arriving at 1 AU may be due to their following a longer, helical path
from Sun to Earth than the usually assumed Parker spiral length of 1.2 AU.
The study implies that the escaping electrons may be accelerated at the
same time as the trapped electrons that produce hard X-ray flare
emissions. When that is the case, there is no need to invoke acceleration
in the CME fronts. |
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