XGAPS: a sub-arcsecond cross-match of Galactic Plane Surveys

TL;DR

XGAPS is a high-precision, cross-matched catalogue combining Gaia DR3 with IGAPS and UKIDSS surveys, enabling detailed studies of Galactic objects within 1-1.5 kpc.

Contribution

This work provides the first sub-arcsecond cross-match of multiple Galactic Plane surveys with Gaia DR3, including proper motion adjustments and a classifier for astrometric quality.

Findings

Catalogue contains nearly 34 million sources.

Proper motion adjustments improve cross-matching accuracy.

Classifier helps identify sources with reliable astrometry.

Abstract

We present a sub-arcsecond cross-match of Gaia Data Release 3 (DR3) against the INT Galactic Plane Surveys (IGAPS) and the United Kingdom Infrared Deep Sky Survey (UKIDSS). The resulting cross-match of Galactic Plane Surveys (XGAPS) provides additional precise photometry ($U_{RGO}$, $g$, $r$, $i$, H$\alpha$, $J$, $H$ and $K$) to the Gaia photometry. In building the catalogue, proper motions given in Gaia DR3 are wound back to match the epochs of the IGAPS constituent surveys (INT Photometric \ha Survey of the Northern Galactic Plane, IPHAS, and the UV-Excess Survey of the northern Galactic plane, UVEX) and UKIDSS, ensuring high proper motion objects are appropriately cross-matched. The catalogue contains 33,987,180 sources. The requirement of $>3\sigma$ parallax detection for every included source means that distances out to 1--1.5 kpc are well covered. In producing XGAPS we have also trained a Random Forest classifier to discern targets with problematic astrometric solutions. Selection cuts based on the classifier results can be used to clean colour-magnitude and colour-colour diagrams in a controlled and justified manner, as well as producing subsets of astrometrically reliable targets. We provide XGAPS as a 111 column table. Uses of the catalogue include the selection of Galactic targets for multi-object spectroscopic surveys as well as identification of specific Galactic populations.