Tycho-2 TDSC Merge Neighbourhood (gaiadr3.tycho2tdsc_merge_neighbourhood)
The table has 2536895 rows, 6 columns.
Description
Table tycho2tdsc_merge_neighbourhood
includes all good neighbours for each matched Tycho2tdscMerge object. A good neighbour for a given Tycho2tdscMerge source is a nearby Gaia object whose position is compatible (within position errors) with the Tycho2tdscMerge target. The cross-match algorithm is not symmetric and searches Tycho2tdscMerge source counterparts in Gaia. The cross-match algorithm is positional and exploits the full 5 parameter covariance matrix of the Gaia astrometric solution when available and the external catalogue positions and position errors. In addition it takes into account the Gaia environment using the local density.
Please note that the cross-match algorithm is a trade-off between multiple requirements, in particular between completeness and correctness. It is thus not limited to a simple cone search.
Reference papers:
- Marrese et al. (2017)
- Marrese et al. (2019)
Attribution
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.
More information can be found on the credit and citation instructions page.
Columns
Name | Type | UCD | Unit | Description |
---|---|---|---|---|
source_id | long |
meta.id meta.main meta.ref |
Unique Gaia source identifier |
|
original_ext_source_id | char | meta.id.cross |
Original External Catalogue source identifier |
|
angular_distance | float | pos.angDistance | arcsec |
Angular Distance between the two sources |
score | double | meta.code |
Score of neighbours |
|
xm_flag | short | meta.code.status |
Cross-match algorithm flag |
|
tycho2tdsc_merge_oid | integer | meta.id.cross |
External Catalogue source identifier |