VLBApls acknowledgements

The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc.

The authors acknowledge the hospitality of JIVE where part of this work was carried out. SF and ZP acknowledge financial support received from the Hungarian Space Office, the Netherlands Organization for Scientific Research (NWO) and the Hungarian Scientific Research Fund (OTKA, grant no. N31721 & T031723). LIG acknowledges partial support from the European Commission's TRM Programme, "Access to Large-Scale Facilities", under contract ERBFMGECT950012 and the European Commission's TRM programme, Research Network Contract ERBFMRXCT 96-0034 "CERES". WKS and ART acknowledge financial support from the Canadian Space Agency.

This research has made use of

• the US Naval Observatory (USNO) Radio Reference Frame Image Database (RRFID),
• the SIMBAD database operated at CDS (Strasbourg, France),
• data from the University of Michigan Radio Astronomy Observatory which is supported by funds from the University of Michigan,
• and the NASA/IPAC Extragalactic Database (NED) which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration.