In the framework of the International VLBI Service for Geodesy and Astrometry (IVS), the Bordeaux Analysis Center produces VLBI images of radio
extragalactic sources (« quasars ») including sources from the International Celestial Reference Frame (ICRF).
Thanks to these images, one can study the sources morphology, which is usually not point-like at VLBI scales, and so limits the precision of the astrometric positions. The astrometric suitability of these sources is determined thanks to other products based on VLBI images such as the « structure correction maps » and the « visibility maps ». All these products are provided to the international scientific community through the BVID.
Technical contact: Arnaud Collioud-Marichallot