2MASS PSC XSC Join

The table links the external catalogue original sourceId (originalExtSourceId) to the corresponding additional numerical identifier (cleanTmassPscXscOid).Both originalExtSourceId and cleanTmassPscXscOid are present in the cross-match output tables (TmassPscXscBestNeighbour and TmassPscXscNeighbourhood). However, in case there are suspected duplicates in the external catalogue, different originalExtSourceId will correspond to the same cleanTmassPscXscOid.In the cross-match output table only the originalExtSourceId of the source with the best astrometry among the suspected duplicates will be listed.

In practice, users may use the originalExtSourceId in the original catalogue to find the matching source with the best astrometry. Users interested to find all matching suspected duplicates should instead use the cleanTmassPscXscOid in the join with the cross-match result tables.See Chapter [chap:crossmatch] for more details on the duplicates in the external catalogues and their treatment in the cross-match computations.</p>