This file is the result of a coordinates match between GCNS and Luca Casagrande´s catalogue of 
photometric metallicities for Southern Sources from SkyMapper 
(http://skymapper.anu.edu.au/_data/sm-gaia/). 
There are around 3000+ (nearest) matches witin a cone search radius of 5 arsec.

Luca´s catalogue uses Gaia DR2 source_id and coordinates. The match to GCNS coordiantes has been
done correcting the later coordiantes from 2016.0 (nominal epoch of eDR3) to 2015.5 (nominal 
epoch for DR2). Given the very small epoch difference, the correction is very small.

The file contains all original entries from GCNS and then Luca´s information regarding [Fe/H] and 
its formal uncertainty, followed by the positional, astrometric, and photometric information for
the matched source from DR2. The name of the columns are self-informative.

Column distance indicates the great circle distance of the best match (smaller than 5 arcsec). 
By plotting, e.g., distance vs G magnitude it is clear that faint targets tend to have large
distances, most likely these matches are spurious. One can also plot G(eDR3-GCNS) vs G(DR2-Luca) for
the matched sources, large discepancies could indicate a spurious match. Please do your own 
evaluation of possible surious matches in a case by case situations - for completeness we have
however kept all matched (nearest) sources with a 5 arscec cone. A rather conservative approach 
to have a clean sample would be to remove all sources with distances larger than about 1 arsec.

For any questions, send me an email. Rene A. Mendez (rmendez@uchile.cl).
