Python code for calculating the Renormalized Unit Weight Error from the Gaia DR2 table columns.
One of the recommendations on the use of Gaia DR2 astrometry is to use the so-called Renormalized Unit Weight Error (RUWE) to filter out sources with potentially bad astrometry, in particular spurious parallaxes or proper motions. Details are in these presentation slides and in this technical note.
This repository provides Python code for calculating the value of the RUWE from the relevant table columns in the Gaia DR2 Archive. An accompanying notebook shows how to use the code by reproducing one of the plots in the above mentioned presentation slides.
NOTE The Gaia DR2 mirror at ARI (Heidelberg) provides the RUWE as a table column, so you can filter on the RUWE values directly in your ADQL query.