1. Joint Institute for VLBI ERIC, Oude Hoogeveensedijk 4, NL-7991 PD Dwingeloo, The Netherlands
2. Mizusawa VLBI Observatory, National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan
3. Korea Astronomy and Space Science Institute, 776 Daedeokdae-ro, Yuseong-gu, Daejeon 34055, Republic of Korea
4. School of Natural Sciences, University of Tasmania, Private Bag 37, Hobart, TAS 7001, Australia
5. Xinjiang Astronomical Observatory, Chinese Academy of Sciences, 150 Science 1-Street, Urumqi, Xinjiang 830011, China
6. Astro Space Center, Lebedev Physical Institute, Russian Academy of Sciences, Leninskiy Prospekt 53, Moscow 119333, Russia
7. INAF – Osservatorio Astronomico di Cagliari, Via della Scienza 5, I-09047 Selargius, Italy
8. Centre for Astronomy, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University, Grudziadzka 5, PL-87-100 Toruń, Poland
9. The University of Western Ontario, 1151 Richmond Street, London, ON N6A 3K7, Canada
10. Hartebeesthoek Radio Astronomy Observatory, PO Box 443, Krugersdorp 1740, South Africa
11. Radio Astronomy and Geodynamics Department of Crimean Astrophysical Observatory, Katsively RT-22, Crimea
12. Lomonosov Moscow State University, Sternberg Astronomical Institute, Moscow 119234, Russia
13. National Radio Astronomy Observatory, PO Box O, 1003 Lopezville Rd., Socorro, NM 87801, USA
14. Sterrewacht Leiden, Leiden University, Postbus 9513, NL-2300 RA Leiden, The Netherlands
15. South African Radio Astronomy Observatory (SARAO), 3rd Floor, The Park, Park Road, Pinelands, Cape Town 7405, South Africa
16. Space Research Unit, Physics Department, North West University, Potchefstroom 2520, South Africa
17. National Astronomical Research Institute of Thailand, 260 M.4, T. Donkaew, Amphur Maerim, Chiang Mai 50180, Thailand
18. University of Science and Technology, Korea (UST), 217 Gajeong-ro, Yuseong-gu, Daejeon 34113, Republic of Korea
19. Astronomical Observatory, Ural Federal University, Lenin Ave. 51, Ekaterinburg 620083, Russia
20. Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69, D-53121 Bonn, Germany
21. Netherlands Institute for Radio Astronomy, Oude Hoogeveensedijk 4, NL-7991 PD Dwingeloo, The Netherlands
22. NRAO, 520 Edgemont Road, Charlottesville, VA 22903, USA
23. Instituto de Radioastronomía y Astrofísica, Universidad Nacional Autónoma de México, Apartado Postal 3-72, Morelia 58089, Mexico
24. INAF – Istituto di Radioastronomia and Italian ALMA Regional Centre, via P. Gobetti 101, I-40129 Bologna, Italy