A first catalogue of automatically selected UV-excess sources from the UVEX survey

TL;DR

This paper presents the first catalogue of UV-excess point sources from the UVEX survey, covering 211 square degrees of the Northern Galactic Plane, identifying various stellar and extragalactic objects using automated selection methods.

Contribution

It introduces an automated algorithm for selecting UV-excess sources from the UVEX survey and provides the first comprehensive catalogue of these sources in the Galactic Plane.

Findings

Catalogue contains 2170 UV-excess sources, including white dwarfs and quasars.

Identified over 9,800 candidate metal-poor or reddened stars.

Discovered 803 objects likely to be late M-giants, T Tauri stars, or planetary nebulae.

Abstract

We present the first catalogue of point-source UV-excess sources selected from the UVEX survey. UVEX images the Northern Galactic Plane in the U, g, r and HeI5875 bands in the Galactic latitude range -5deg<b<+5deg. Through an automated algorithm, which works on a field-to-field basis, we select blue UV-excess sources in 211 square degrees from the (U-g) vs. (g-r) colour-colour diagram and the g vs. (U-g) and g vs. (g-r) colour-magnitude diagrams. The UV-excess catalogue covers the magnituderange 14<g<22.5, contains 2170 sources and consists of a mix of white dwarfs, post-common-envelope objects, interacting binaries, quasars and AGN. Two other samples of outliers were found during the selection: i) a 'subdwarf' sample, consisting of no less than 9872 candidate metal-poor stars or lightly reddened main-sequence stars, and ii) a 'purple' sample consisting of 803 objects, most likely a mix of reddened late M-giants, T Tauri stars, planetary nebulae, symbiotic stars and carbon stars. Cross-matching the selected UV-excess catalogue with other catalogues aids with the first classification of the different populations and shows that more than 99% of our selected sources are unidentified sources.