1. Department of Physics and Astronomy; Uppsala University; Uppsala Sweden
2. Université de Toulouse, UPS-OMP, IRAP; Toulouse France
3. CNRS, Institut de Recherche en Astrophysique et Planétologie; Toulouse France
4. Leibniz Institute for Astrophysics Potsdam (AIP); Potsdam Germany
5. INAF, Osservatorio Astrofisico di Catania; Catania Italy
6. Institut für Astrophysik; Georg-August-Universität Göttingen; Göttingen Germany
7. Niels Bohr Institute; University of Copenhagen; Copenhagen Denmark
8. Department of Astronomy; University of Michigan; Ann Arbor Michigan
9. LUPM, Université de Montpellier, CNRS; Montpellier France
10. Department of Astronomy; Stockholm University; Stockholm Sweden