Vendredi 13 Juin 2025

Dernière modification
le 23 11 2009

Bienvenue sur la page perso
de Stéphane Régnier



 Nouveau
Albums photo Espagne, Italie et Slovaquie
 CV
CV détaillé
Liste des publications
Highlights
 Physique solaire
Institut d'Astrophysique Spatiale
Université du Montana
RSSD at ESA/ESTEC
Université de St Andrews
 Albums photos
Écosse
Espagne
France
Grèce
Italie
Rép. Tchèque
Slovaquie
USA
 Généalogie
 Histoire
Documents non datés
Guerre 14-18
Guerre 39-45
 Peintres
Salvador DALI
Victor VASARELY
 Philatélie
 Liens utiles

Crédit agricole de la Somme
Bourse-Les échos
E-Bay France

Publication - Highlights

Highlights

(Randomly generated highlights)


A new view of quiet-Sun topology from Hinode/SOT
S. Régnier, C. E. Parnell, A. L. Haynes
2008, A&A, 484, L47

Data Hinode/SOT-NFI
Method Potential field extrapolation; null point finding
Results The number of null points in the solar atmosphere: 54% in the photosphere, 44% in the chromosphere and only 2% in the corona. This reveals the complexity of the photospheric and chromospheric quiet-Sun magnetic fields.

Abstract With the recent launch of the Hinode satellite our view of the nature and evolution of quiet-Sun regions has been improved. In light of the new high resolution observations, we revisit the study of the quiet Sun's topological nature. Topology is a tool to explain the complexity of the magnetic field, the occurrence of reconnection processes, and the heating of the corona. This Letter aims to give new insights to these different topics. Using a high-resolution Hinode/SOT observation of the line-of-sight magnetic eld on the photosphere, we calculate the three dimensional magnetic field in the region above assuming a potential field. From the 3D field, we determine the existence of null points in the magnetic configuration. From this model of a continuous field, we find that the distribution of null points with height is significantly different from previous studies. In particular, the null points are mainly located above the bottom boundary layer in the photosphere (54%) and in the chromosphere (44%) with only a few null points in the corona (2%). The density of null points (expressed as the ratio of the number of null points to the number of photospheric magnetic fragments) in the solar atmosphere is estimated to be between 3% and 8% depending on the method used to identify the number of magnetic fragments on the observed photosphere. This study reveals that the heating of the corona by magnetic reconnection at coronal null points is unlikely. Our findings do not rule out the heating of the corona at other topological features. We also reveal the topological complexity of the chromosphere as strongly suggested by recent observations from Hinode/SOT.

bottom  

 E-mail | Ajouter aux favoris

Copyright © 2004 Stéphane Régnier