1. The University of Western Ontario, 1151 Richmond Street, London, ON N6A 3K7, Canada
2. Hartebeesthoek Radio Astronomy Observatory, PO Box 443, Krugersdorp 1741, South Africa
3. Mizusawa VLBI Observatory, National Astronomical Observatory of Japan (NAOJ), 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan
4. NRAO, 520 Edgemont Rd, Charlottesville, VA 22903, USA
5. Netherlands Institute for Radio Astronomy, ASTRON, NL-7991 PD Dwingeloo, the Netherlands
6. Sydney Institute for Astronomy (SIfA), School of Physics, University of Sydney, NSW 2006, Australia
7. Korea Astronomy and Space Science Institute, 776 Daedeokdae-ro, Yuseong-gu, Daejeon 34055, Republic of Korea
8. Dublin Institute for Advanced Studies, Astronomy and Astrophysics Section, 31 Fitzwilliam Place, D02 XF86, Dublin 2, Ireland
9. Center for Astrophysics, GuangZhou University, Guangzhou 510006, China
10. Shanghai Astronomical Observatory, Chinese Academy of Sciences, 80 Nandan Road, Shanghai 200030, China
11. Space Research Unit, Physics Department, North West University, Potchefstroom 2520, South Africa
12. Department of Physics and Astronomy, Faculty of Physical Sciences, University of Nigeria, Carver Building, 1 University Road, 410001, Nsukka Nigeria
13. CSIRO Astronomy and Space Science, CSIRO Parkes Observatory, PO Box 276 Parkes, NSW 2870, Australia
14. Max Planck Institute for Astronomy, Königstuhl 17, D-69117 Heidelberg, Germany
15. Institute for Quantum Computing and Department of Physics and Astronomy, The University of Waterloo, 200 University Ave. West, Waterloo, Ontario N2L 3G1, Canada
16. Perimeter Institute for Theoretical Physics, Waterloo, ON N2L 2Y5, Canada
17. Center for Astronomy, Ibaraki University, 2-1-1 Bunkyo, Mito, Ibaraki 310-8512, Japan
18. Thüringer Landessternwarte, Sternwarte 5, D-07778 Tautenburg, Germany
19. Astronomical Observatory, Institute for Natural Sciences and Mathematics, Ural Federal University, 19 Mira street, Ekaterinburg 620002, Russia