1. Niels Bohr International Academy, Niels Bohr Institute, University of Copenhagen , Blegdamsvej 17, DK-2100 Copenhagen , Denmark
2. INAF – Osservatorio Astronomico di Roma , Via Frascati 33, I-00078 Monte Porzio Catone (RM) , Italy
3. ASI – Space Science Data Center, Via del Politecnico snc , I-00133 Roma , Italy
4. Gran Sasso Science Institute , Via F. Crispi 7, I-67100 L’Aquila , Italy
5. INFN/Laboratori Nazionali del Gran Sasso , Via G. Acitelli 22, I-67100, Assergi (AQ) , Italy
6. INAF, Osservatorio Astrofisico di Arcetri , L.go E. Fermi 5, I-50125 Firenze , Italy
7. Observatoire de Paris, PSL Research University , LUTH, 5 Place J. Janssen, F-92195 Meudon , France