1. Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA, UK
2. York University, 4700 Keele Street, Toronto, ON M3J 1P3, Canada
3. Cosmic Dawn Center, Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, DK-2100 Copenhagen Ø, Denmark
4. European Southern Observatory, D-85748 Garching bei München, Germany
5. Max-Planck Institut für Astronomie, Königstuhl 17, D-69117 Heidelberg, Germany
6. Sterrenkundig Observatorium, Universiteit Gent, Krijgslaan 281 S9, B-9000 Gent, Belgium
7. Astronomy Department, Yale University, 52 Hillhouse Ave, New Haven, CT 06511, USA
8. Department of Physics and Astronomy, University of Waterloo, Waterloo, ON N2L 3G1, Canada
9. Department of Physics and Astronomy, University of California Riverside, 900 University Avenue, Riverside, CA 92521, USA
10. Departamento de Astronomía, Facultad de Ciencias Físicas y Matemáticas, Universidad de Concepción, Concepción, Chile
11. Department of Physics and Astronomy, Tufts University, 574 Boston Avenue Suites 304, Medford, MA 02155, USA
12. Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138, USA
13. MIT Kavli Institute for Astrophysics and Space Research, 70 Vassar St, Cambridge, MA 02109, USA
14. Department of Astronomy and Astrophysics, University of Toronto, 50 St. George Street, Toronto, ON M5S 3H4, Canada