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Caractérisation de l'Environnement Magnétique de la Couronne Solaire

Abstract : The magnetic field is known to play a major role in the structure and dynamic of the solar corona. However, it cannot be directly measured in the three dimensional (3D) space but only on the Sun's surface (called photosphere) and provided as a vector magnetogram. Using these maps with the only assumption that the field is force-free, one is able to reconstruct the magnetic field in a 3D domain. In the framework of this thesis, the magnetic field reconstruction has been applied to three different topics of solar physics. First, the emergence of a magnetic structure across the photosphere has been studied. Based on the data measured by the telescope THEMIS in September 2005, the reconstruction highlights the presence of a twisted flux rope in equilibrium as the pre-eruptive magnetic config- uration. The second study focuses on the determination of the magnetic structure supporting the cold matter of a filament. Some data, measured in April 2007 by Hinode, has been used and it has been shown that the underlying magnetic structure of the filament was a twisted flux rope in a stable equilibrium state. The last study deals with the evolution of an emerging active region, from which an eruption originated in December 2006. The sequence of reconstructions shows the creation and expansion of a twisted flux rope, followed by its disappearance after the eruption takes place. Possible mechanisms for its eruption are discussed. This work clearly shows the crucial role played by the twisted flux rope to better understand both the studied solar phenomena and the link between the observations and the theories.
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https://pastel.archives-ouvertes.fr/pastel-00649215
Contributor : Aurélien Canou <>
Submitted on : Wednesday, December 7, 2011 - 1:32:01 PM
Last modification on : Thursday, December 19, 2019 - 2:06:01 PM
Long-term archiving on: : Friday, November 16, 2012 - 2:45:51 PM

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  • HAL Id : pastel-00649215, version 1

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Aurélien Canou. Caractérisation de l'Environnement Magnétique de la Couronne Solaire. Astrophysique stellaire et solaire [astro-ph.SR]. Ecole Polytechnique X, 2011. Français. ⟨pastel-00649215⟩

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