1. Institut für Theoretische Physik, Lehrstuhl IV: Weltraum-und Astrophysik, Ruhr-Universität Bochum, D-44780 Bochum, Germany
2. Centre for Mathematical Plasma Astrophysics, Celestijnenlaan 200B, 3001 Leuven, Belgium
3. Institute for Physical Science and Technology, University of Maryland, College Park, Maryland 20742, USA
4. School of Space Research, Kyung Hee University, Yongin-Si, Gyeonggi-Do 446-701, South Korea
5. SUPA, Physics Department, Strathclyde University, John Anderson Building, Glasgow, Scotland G4 0NG, United Kingdom