1. Cavendish Laboratory, University of Cambridge, 19 J. J. Thomson Ave., Cambridge CB3 0HE, UK
2. Kavli Institute for Cosmology, University of Cambridge, Madingley Road, Cambridge CB3 0HA, UK
3. INAF – Osservatorio Astronomico di Roma, via Frascati 33, I-00078 Monteporzio, Italy
4. Centro Fermi, Museo Storico della Fisica e Centro Studi e Ricerche ‘Enrico Fermi’, Piazza del Viminale 1, Roma I-0184, Italy
5. Scuola Normale Superiore, Piazza dei Cavalieri 7, I-56126 Pisa, Italy
6. NRC Herzberg, 5071 West Saanich Rd, Victoria, BC V9E 2E7, Canada
7. Leiden Observatory, Leiden University, PO Box 9513, NL-2300 RA Leiden, the Netherlands
8. Department of Physics, Lancaster University, Lancaster LA1 4YB, UK
9. Observatoire de Genève, Université de Genève, 51 Ch. des Maillettes, CH-1290 Versoix, Switzerland
10. INAF – Osservatorio Astronomico di Bologna, via P. Gobetti 93/3, I-40129 Bologna, Italy
11. Núcleo de Astronomía, Facultad de Ingeniería, Universidad Diego Portales, Av. Ejército 441, Santiago, Chile