1. Astronomisches Rechen-Institut, Zentrum für Astronomie der Universität Heidelberg, Mönchhofstraße 12-14, D-69120 Heidelberg, Germany
2. Max-Planck Institut für Astronomie, Königstuhl 17, D-69117 Heidelberg, Germany
3. Centre for Astrophysics Research, University of Hertfordshire, Hatfield AL10 9AB, UK
4. Astrophysics Research Institute, Liverpool John Moores University, IC2, Liverpool Science Park, 146 Brownlow Hill, Liverpool L3 5RF, UK
5. Joint ALMA Observatory, Alonso de Cordova 3107, Vitacura, Santiago, Chile
6. National Astronomical Observatory of Japan, Alonso de Cordova 3788, 61B Vitacura, Santiago, Chile
7. National Radio Astronomy Observatory, PO Box O 1009, Lopezville Drive, Socorro, NM 87801, USA
8. Max-Planck Institut für Extraterrestrische Physik, Giessenbachstraße 1, D-85748 Garching, Germany
9. Argelander Institute for Astronomy, University of Bonn, Auf dem Hügel 71, D-53121 Bonn, Germany
10. University of Connecticut, Department of Physics, 2152 Hillside Road, U-3046, Storrs, CT 06269, USA
11. Joint Institute for VLBI ERIC (JIVE), Postbus 2, NL-7990 AA Dwingeloo, the Netherlands
12. School of Mathematical and Physical Sciences, University of Newcastle, University Drive, Callaghan NSW 2308, Australia
13. Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138, USA
14. Physics Department, Brandeis University, 415 South Street, Waltham, MA 02453, USA
15. I. Physikalisches Institut, Universität zu Köln, Zülpicher Straße 77, D-50937 Köln, Germany