1. Department of Astronomy, Columbia University, 550 West 120th Str, New York, NY 10027, USA
2. Department of Astronomy, University of Wisconsin – Madison, 475 N Charter Str, Madison, WI 53706, USA
3. Department of Physics and Astronomy, West Virginia University, PO Box 6315, Morgantown, WV 26506, USA
4. Center for Gravitational Waves and Cosmology, West Virginia University, Chestnut Ridge Research Building, Morgantown, WV 26505, USA
5. Adjunct Astronomer at Green Bank Observatory, Green Bank, WV 24944, USA
6. Department of Astronomy, University of Massachusetts, Amherst, MA 01003, USA
7. School of Earth and Space Exploration, Arizona State University, 781 Terrace Mall, Tempe, AZ 85287 USA
8. National Radio Astronomy Observatory, PO Box 0, Socorro, NM 87801, USA
9. Department of Physics and Astronomy, Rutgers, The State University of New Jersey, Piscataway, NJ 08854-8019, USA
10. ASTRON, the Netherlands Institute for Radio Astronomy, Postbus 2, Dwingeloo NL-7900AA, the Netherlands
11. Kapteyn Astronomical Institute, University of Groningen, Landleven 12, 9747 AD, Groningen, the Netherlands
12. Department of Physics, Virginia Tech, 850 West Campus Drive, Blacksburg, VA 24061, USA
13. International Centre for Radio Astronomy Research, The University of Western Australia, Crawley, WA 6009, Australia
14. Australian Research Council, Centre of Excellence for All-sky Astrophysics (CAASTRO), Australia
15. Department of Astronomy, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 03722, Korea
16. Max Planck Institute for Astronomy, Knigstuhl 17, D-69117 Heidelberg, Germany