Tycho-2 TDSC Merge Best Neighbour (gaiaedr3.tycho2tdsc_merge_best_neighbour)

The table has 2518330 rows, 6 columns.


Tycho2TDSCmerge BestNeighbour table lists each matched external cat-alogue object with its best neighbour in Gaia. The cross-match algorithmis not symmetric and searches Tycho2TDSCmerge sources counterpartsin Gaia.The best neighbour is chosen among good neighbours as the one with thehighest value of the figure of merit, which evaluates the ratio betweentwo opposite models/hypotheses: the counterpart candidate is a match orit is found by chance. Good neighbours are nearby objects in Gaia whoseposition is compatible within position errors with the external catalogue target.


If you have used Gaia data in your research, please use the following acknowledgement:

This work has made use of data from the European Space Agency (ESA) mission Gaia (https://www.cosmos.esa.int/gaia), processed by the Gaia Data Processing and Analysis Consortium (DPAC, https://www.cosmos.esa.int/web/gaia/dpac/consortium). Funding for the DPAC has been provided by national institutions, in particular the institutions participating in the Gaia Multilateral Agreement.

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Name Type UCD Unit Description
source_id long meta.id
Dimensionless Unique Gaia source identifier
original_ext_source_id char meta.id.cross Dimensionless Original External Catalogue source identifier
angular_distance float pos.angDistance Angle[arcsec] Angular Distance between the two sources
xm_flag short meta.code.status Dimensionless Cross-match algorithm flag
tycho2tdsc_merge_oid int meta.id.cross Dimensionless External Catalogue source identifier
number_of_neighbours short meta.number Dimensionless Number of neighbours in Gaia Catalogue