1. Department of Physics, Engineering Physics & Astronomy, Queen’s University, Kingston, ON K7L 3N6, Canada
2. Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69, 53121 Bonn, Germany
3. Faculty of Physics and Astronomy, Astronomical Institute (AIRUB), Ruhr University Bochum, 44780 Bochum, Germany
4. Department of Physics & Astronomy, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
5. Hamburg Observatory, Universität Hamburg, Gojenbergsweg 112, 21029 Hamburg, Germany
6. Purple Mountain Observatory, Chinese Academy of Sciences, 10 Yuanhua Road, Nanjing 210023, China
7. Department of Astronomy, Xiamen University, 422 Siming South Road, Xiamen 361005, China
8. National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22903, USA
9. Kavli Institute for Particle Astrophysics and Cosmology, SLAC, 2575 Sand Hill Road, M/S 29, Menlo Park, CA 94025, USA
10. Department of Physics & Astronomy, University of New Mexico, 210 Yale Blvd. NE, Albuquerque, NM 87106, USA
11. Department of Physics and Astronomy, University of Calgary, 2500 University Drive NW, Calgary, AB T2N 1N4, Canada
12. Max Planck Institute for Extraterrestrial Physics, Gießenbachstraße 1, 85748 Garching, Germany
13. Astronomy Department, New Mexico State University, Las Cruces, NM 88003, USA
14. Department of Astronomy, University of Massachusetts, North Pleasant Street, Amherst, MA 01003-9305, USA
15. Departamento Astronomía Extragaláctica, Instituto de Astrofísica de Andalucía (IAA-CSIC), Glorieta de la Astronomía s/n, 18008 Granada, Spain