1. Institute for Computational Cosmology; Durham University; South Road; Durham; DH1 3LE
2. NASA, Ames Research Center; Moffett Field; CA 94035; USA
3. Institute for Astronomy; University of Edinburgh; Blackford Hill; Edinburgh; EH9 3HJ
4. European Southern Observatory; Karl Schwarzschild Straße 2; 85748; Garching; Germany
5. CSIRO Astronomy and Space Science; Australia Telescope National Facility; PO Box 76; Epping; NSW; 1710; Australia
6. Department of Physics and Astronomy; University College London; Gower Street; London; WC1E 6BT
7. Astronomisches Institut; Ruhr-Universität Bochum; Universitätsstraße 150; 44801; Bochum; Germany
8. UK Astronomy Technology Centre; Science and Technology Facilities Council; Royal Observatory; Blackford Hill; Edinburgh; EH9 3HJ
9. Centre for Astrophysics Research; Science & Technology Research Institute; University of Hertfordshire; Hatfield; Herts; AL10 9AB
10. GEPI; Observatoire de Paris; UMR 8111; CNRS; Université Paris Diderot; 5 place Jules Janssen; 92190; Meudon; France
11. Institut d'Astrophysique Spatiale; Université Paris Sud 11; Orsay; France
12. Leiden Observatory; University of Leiden; PO Box 9513; 2300; RA Leiden; the Netherlands