1. Department of Science and Technology (ITN), Linköping University, 60174 Norrköping, Sweden
2. Univ Lyon, ENS de Lyon, Univ Lyon 1, CNRS, Centre de Recherche Astrophysique de Lyon UMR5574, F-69230 Saint-Genis-Laval, France
3. Laboratoire Univers et Particules de Montpellier (LUPM), Université de Montpellier, CNRS/IN2P3, CC72, place Eugène Bataillon, F-34095 Montpellier Cedex 5, France
4. Astrophysics Research Center of the Open University (ARCO), The Open University of Israel, P.O. Box 808, Ra'anana 4353701, Israel