1. Department of Physics and Astronomy, University of Pittsburgh, 3941 O’Hara Street, Pittsburgh, PA 15260, USA
2. Pittsburgh Particle Physics, Astrophysics, and Cosmology Center (PITT PACC), Pittsburgh, PA 15260, USA
3. Center for Cosmology, Department of Physics and Astronomy, University of California, 4129 Reines Hall, Irvine, CA 92697, USA
4. Center for Astrophysics | Harvard & Smithsonian, 60 Garden Street, Cambridge, MA 02138, USA
5. Department of Physics and Astronomy, University of Leicester, University Road, Leicester LE2 3RJ, UK
6. Centre for Astronomy and Particle Theory, University of Nottingham, Nottingham NG7 2RD, UK
7. Department of Astronomy, University of California, Berkeley, CA 94720, USA
8. Department of Physics, University of California, Berkeley, CA 94720, USA
9. New York University Abu Dhabi, PO Box 129188, Abu Dhabi, United Arab Emirates
10. UCO/Lick Observatory and Department of Astronomy and Astrophysics, University of California, Santa Cruz, 1156 High Street, Santa Cruz, CA 95064, USA
11. Astronomy Department, Orange Coast College, Costa Mesa, CA 92626, USA
12. Department of Physics and Astronomy, Colby College, Waterville, ME 04961, USA
13. Max-Planck-Institut für Extraterrestrische Physik, Giessenbachstraße, D-85748 Garching, Germany
14. Centre for Extragalactic Astronomy, Department of Physics, Durham University, Durham DH1 3LE, UK
15. Lawrence Berkeley National Laboratory, One Cyclotron Road, Berkeley, CA 94720, USA
16. Department of Physics, University of Connecticut, 2152 Hillside Road, Unit 3046, Storrs, CT 06269, USA
17. MMT/Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721, USA
18. Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721, USA
19. Department of Physics and Astronomy, University of Kentucky, 505 Rose Street, Lexington, KY 40506-0055, USA