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| Titel |
Particle acceleration in helical magnetic fields in the corona |
| VerfasserIn |
Mykola Gordovskyy, Philippa Browning, Michael Bareford, Rui Pinto, Eduard Kontar, Nicolas Bian |
| Konferenz |
EGU General Assembly 2014
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 16 (2014) |
| Datensatznummer |
250087619
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| Publikation (Nr.) |
 EGU/EGU2014-1677.pdf |
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| Zusammenfassung |
| Twisted magnetic fields should be ubiquitous in the solar corona. Emerging twisted
ropes as well as complex photospheric motions provide continuous influx of the
magnetic helicity. Twisted coronal fields, in turn, contain excess magnetic energy,
which can be released, causing solar flares and other explosive phenomena. It has
been shown recently, that reconnection in helical magnetic structures results in
particle acceleration distributed within large volume, including the lower corona
and chromosphere. Hence, the magnetic reconnection and particle acceleration
scenario involving magnetic helicity can be a viable alternative to the standard
flare model, where particles are accelerated in a small volume located in the upper
corona.
We discuss our recent results on the energy release and particle acceleration during
magnetic reconnection in twisted coronal loops. Evolution of various helical structures is
described in terms of resistive MHD, including heat conduction and radiation. We consider
the effects of field topology and photospheric motions on the energy accumulation and
release. In particular, we focus on scenarios with continuous helicity injection, leading to
recurrent explosive events.
Using the obtained MHD models, ion and electron acceleration is investigated, taking into
account Coulomb collisions. We derive time-dependent energy spectra and spatial
distribution for these species, and calculate resulting non-thermal radiation intensities. Based
on the developed numerical models, we investigate observational implications of particle
acceleration in helical magnetic structures. Thus, we compare temporal variations of thermal
and non-thermal emission in different configurations. Furthermore, we consider spatial
distributions of the thermal EUV and X-ray emission and non-thermal X-ray emission and
compare them with observational data. |
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