[1] Nicolaus Copernicus Astron Ctr, PL-00716 Warsaw, Poland
[2] Stanford Univ, Dept Phys, Kavli Inst Particle Astrophys & Cosmol, Stanford, CA 94309 USA
[3] CSIC, Inst Astrofis Andulucia, E-18080 Granada, Spain
[4] Univ Zurich, Inst Theoret Phys, CH-8057 Zurich, Switzerland
[5] Swiss Fed Inst Technol, Dept Phys, Inst Astron, CH-8093 Zurich, Switzerland
[6] CNRS, UMR 7095, Inst Astrophys Paris, F-75014 Paris, France
[7] Univ Paris 06, F-75014 Paris, France
[8] CNRS, UMR 8111, GEPI, F-92195 Meudon, France
[9] Univ Paris 07, Observ Paris, F-92195 Meudon, France