1. Department of Physics and Astronomy, University of British Columbia, 6224 Agricultural Road, Vancouver, BC V6T 1Z1, Canada
2. Anton Pannekoek Institute for Astronomy, University of Amsterdam, Science Park 904, NL-1098 XH Amsterdam, the Netherlands
3. ASTRON, Netherlands Institute for Radio Astronomy, Oude Hoogeveensedijk 4, NL-7991 PD Dwingeloo, the Netherlands
4. Department of Physics and Astronomy, Western Kentucky University, 1906 College Heights Blvd., Bowling Green, KY 42101, USA
5. Department of Physics and McGill Space Institute, McGill University, Montreal, QC H3A 2T8, Canada
6. Department of Physics and Astronomy, West Virginia University, Morgantown, WV 26506, USA
7. Center for Gravitational Waves and Cosmology, West Virginia University, Chestnut Ridge Research Building, Morgantown, WV 26505, USA
8. Green Bank Observatory, PO Box 2, Green Bank, WV 24944, USA
9. National Radio Astronomy Observatory, Charlottesville, VA 22903, USA
10. New York University Abu Dhabi, Saadiyat Island, Abu Dhabi, PO Box 129188, UAE
11. Eureka Scientific, Inc. Oakland, CA 94602, USA
12. National Radio Astronomy Observatory, 1003 Lopezville Road, Socorro, NM 87801, USA