H. Hirabayashi, ^* H. Hirosawa, H. Kobayashi, Y. Murata, P. G. Edwards, E. B. Fomalont, K. Fujisawa, T. Ichikawa, T. Kii, J. E. J. Lovell, G. A. Moellenbrock, R. Okayasu, M. Inoue, N. Kawaguchi, S. Kameno, K. M. Shibata, Y. Asaki, T. Bushimata, S. Enome, S. Horiuchi, T. Miyaji, T. Umemoto, V. Migenes, K. Wajima, J. Nakajima, M. Morimoto, J. Ellis, D. L. Meier, D. W. Murphy, R. A. Preston, J. G. Smith, S. J. Tingay, D. L. Traub, R. D. Wietfeldt, J. M. Benson, M. J. Claussen, C. Flatters, J. D. Romney, J. S. Ulvestad, L. R. D'Addario, G. I. Langston, A. H. Minter, B. R. Carlson, P. E. Dewdney, D. L. Jauncey, J. E. Reynolds, A. R. Taylor, P. M. McCulloch, W. H. Cannon, L. I. Gurvits, A. J. Mioduszewski, R. T. Schilizzi, R. S. Booth

High angular resolution images of extragalactic radio sources are being made with the Highly Advanced Laboratory for Communications and Astronomy (HALCA) satellite and ground-based radio telescopes as part of the Very Long Baseline Interferometry (VLBI) Space Observatory Programme (VSOP). VSOP observations at 1.6 and 5 gigahertz of the milli-arc-second-scale structure of radio quasars enable the quasar core size and the corresponding brightness temperature to be determined, and they enable the motions of jet components that are close to the core to be studied. Here, VSOP images of the gamma-ray source 1156+295, the quasar 1548+056, the ultraluminous quasar 0014+813, and the superluminal quasar 0212+735 are presented and discussed.

H. Hirabayashi, H. Hirosawa, H. Kobayashi, Y. Murata, P. G. Edwards, E. B. Fomalont, K. Fujisawa, T. Ichikawa, T. Kii, J. E. J. Lovell, G. A. Moellenbrock, and R. Okayasu are with the Institute of Space and Astronautical Science, Sagamihara, Kanagawa 229-8510, Japan. M. Inoue, N. Kawaguchi, S. Kameno, K. M. Shibata, Y. Asaki, T. Bushimata, S. Enome, S. Horiuchi, T. Miyaji, and T. Umemoto are with the National Astronomical Observatory, Mitaka, Tokyo 181-8588, Japan. V. Migenes is with the National Astronomical Observatory, Mitaka, Tokyo 181-8588, Japan, and the University of Guanajuato, Guanajuato, CP 36000, Mexico. K. Wajima is at Ibaraki University, Mito, Ibaraki, 310-8512 Japan. J. Nakajima is with the Communications Research Laboratory, Kashima, Ibaraki 314-0012, Japan. M. Morimoto is at Kagoshima University, Kagoshima 890-0064, Japan. J. Ellis, D. L. Meier, D. W. Murphy, R. A. Preston, J. G. Smith, S. J. Tingay, D. L. Traub, and R. D. Wietfeldt are with the Jet Propulsion Laboratory, 4800 Oak Grove Drive, Pasadena, CA 91109, USA. J. M. Benson, M. J. Claussen, C. Flatters, J. D. Romney, and J. S. Ulvestad are with the National Radio Astronomy Observatory, Socorro, NM 87801, USA. L. R. D'Addario, G. I. Langston, and A. H. Minter are with the National Radio Astronomy Observatory, Green Bank, WV 24944, USA. B. R. Carlson and P. E. Dewdney are with the Dominion Radio Astrophysical Observatory, Hertzberg Institute of Astrophysics, National Research Council of Canada, Penticton, British Columbia V2A 6K3, Canada. D. L. Jauncey and J. E. Reynolds are with the Australia Telescope National Facility, Epping, New South Wales 2122, Australia. A. R. Taylor is at the University of Calgary, Calgary, Alberta, T2N 1N4, Canada. P. M. McCulloch is at the University of Tasmania, Hobart, Tasmania 7000, Australia. W. H. Cannon is with the Center for Research in Earth and Space Technology/York University, Ontario, M3J 3K1 Canada. L. I. Gurvits is with the Joint Institute for VLBI in Europe, 7991 PD Dwingeloo, Netherlands, and the Astro Space Center, P.N. Lebedev Physical Institute, Moscow 117810 GSP-1, Russia. A. J. Mioduszewski is with the Joint Institute for VLBI in Europe, 7991 PD Dwingeloo, Netherlands, and the National Radio Astronomy Observatory, Socorro, NM 87801, USA. R. T. Schilizzi is with the Joint Institute for VLBI in Europe, 7991 PD Dwingeloo, Netherlands. R. S. Booth is with the Onsala Space Observatory, Chalmers University of Technology, S-43992 Onsala, Sweden.
^*   To whom correspondence should be addressed. E-mail: hirax{at}vsop.isas.ac.jp