The Unified Astronomy Thesaurus (UAT) is an open, interoperable and community-supported thesaurus which unifies the existing divergent and isolated Astronomy & Astrophysics thesauri into a single high-quality, freely-available open thesaurus formalizing astronomical concepts and their inter-relationships. The UAT builds upon the existing IAU Thesaurus with major contributions from the Astronomy portions of the thesauri developed by the Institute of Physics Publishing and the American Institute of Physics. We expect that the Unified Astronomy Thesaurus will be further enhanced and updated through a collaborative effort involving broad community participation. See Website at: http://astrothesaurus.org/ . (UAT version used for WDCOSF: https://github.com/katieefrey/UAT/blob/master/UAT.rdf )
Please note that we are using the respective vocabularies essentially as they are provided from the respective maintainers. In some cases we made slight formal modifications, like adding language attributes "xml:lang" to <skos:prefLabel>, <skos:altLabel> etc. or changed <dc:description> to <skos:definition> for the reason of internal homogeneity. IN NO CASE we made conceptual changes like e.g. reordering of hierarchical relations (even if in some rare cases we thought it would make sense). So if you find questionable relations when browsing through the respective vocabularies, please send a message to the respective maintainers.