| Affiliation: | University of Manchester, Jodrell Bank Observatory, Macclesfield, Cheshire SK11 9DL;Joint Institute for VLBI in Europe, Postbus 2, 7990 AA Dwingeloo, the Netherlands;Department of Physics and Astronomy, University of Pennsylvania, 209 S. 33rd St, Philadelphia, PA 19104-6396, USA;Harvard-Smithsonian Centre for Astrophysics, 60 Garden Street, Cambridge, MA 02138, USA;Kapteyn Astronomical Institute, Postbus 800, 9700 AV Groningen, the Netherlands;ASTRON, Postbus 2, 7990 AA Dwingeloo, the Netherlands;California Institute of Technology, Pasadena, CA 91125, USA;National Radio Astronomy Observatory, PO Box 0, Socorro, NM 87801, USA;Space Telescope Scientific Institute, 3700 San Martin Dr., Baltimore, MD 21218, USA |
