1. Department of Physics, Stanford University, 382 Via Pueblo Mall, Stanford, CA 94305-4060, USA
2. Kavli Institute for Particle Astrophysics and Cosmology, Stanford University, 452 Lomita Mall, Stanford, CA 94305-4085, USA
3. Institute of Cosmology and Gravitation, University of Portsmouth, Burnaby Road, Portsmouth, PO1 3FX, UK
4. SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA
5. Marshall Space Flight Center, Huntsville, AL 35812 USA
6. Department of Physics and Astronomy, Stony Brook University, Stony Brook, NY 11794, USA
7. Department of Astronomy and Astrophysics, The Pennsylvania State University, University Park, PA 16802, USA
8. Institute for Gravitation and the Cosmos, Department of Physics, Pennsylvania State University, University Park, PA 16802, USA
9. Department of Physics, 104 Davey Laboratory, The Pennsylvania State University, University Park, PA 16802, USA
10. School of Astronomy and Space Science, Nanjing University, Nanjing 210093, China
11. CAS Key Laboratory for Research in Galaxies and Cosmology, Department of Astronomy, University of Science and Technology of China, Hefei 230026, China
12. Minnesota Institute for Astrophysics, University of Minnesota, 115 Union St. SE, Minneapolis, MN 55455, USA