1. Department of Physics, University of Warwick, Gibbet Hill Road, Coventry CV4 7AL, UK
2. Department of Astrophysics/IMAPP, Radboud University, Nijmegen, The Netherlands
3. Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138, USA
4. Department of Astronomy, University of California, Berkeley, CA 94720, USA
5. NASA Goddard Space Flight Center, 8800 Greenbelt Road, Greenbelt, DMD 20771, USA
6. Joint Space-Science Institute, University of Maryland, College Park, MD 20742, USA
7. Department of Physics, The George Washington University, Washington, DC 20052, USA
8. College of Science and Mathematics, University of the Virgin Islands, #2 Brewers Bay Road, Charlotte Amalie, USVI 00802
9. Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218, USA
10. Dark Cosmology Centre, Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, DK-2100 Copenhagen ø, Denmark
11. Centre for Astrophysics and Cosmology, Science Institute, University of Iceland, Dunhagi 5, 107 Reykjavik, Iceland
12. Department of Physics and Astronomy, University of Leicester, University Road, Leicester LE1 7RH, UK
13. Astrophysics Research Institute, Liverpool John Moores University, 146 Brownlow Hill, Liverpool L3 5RF, UK