Cross-identification of radio sources from a large number of heterogenuous catalogues using VO tools

The SPECFIND catalogue of radio cross-identifications and spectra, which is available in VizieR (Ochsenbein et al. 2000), has been used to search for Gigahertz peaked source candidates. These sources were observed quasisimultaneously with the Effelsberg 100-m radio telescope at 6 cm (4.85 GHz), 2.8 cm (10.45 GHz), and 9 mm (32 GHz). It turned out that this is an efficient procedure to discover new Gigahertz peaked sources, which are believed to be AGNs at the beginning of their radio evolution. A new SPECFIND V2.0 catalogue is presented. It contains the cross-identification of 87000 radio objects from 105 catalogues or 3.76 million radio sources. With an increase of 8 % of available sources we increase the number of radio objects with associated radio spectra by 25 %. Going from 20 catalogues in the previous SPECFIND release to 105 catalogues in the new release was only possible due to the development of three Virtual Observatory (VO) tools within the European VO-TECH project. These new tools (i) identify pertinent radio catalogues in the VO registry using Unified Content Descriptors (UCDs), (ii) extract relevant data, and (iii) normaliz e these for the determination of radio spectra.