Mid-infrared AGN selection criteria comparison for LQAC-6 dense field correction: Towards celestial reference frame densification
Year: 2026
Type: article
Abstract: Context. The sixth version of the Large Quasar Astrometric Catalogue (LQAC-6) is a compilation of over 2 million quasars and active galactic nuclei (AGNs) whose study is of particular interest notably in cosmology and for enhancing celestial reference frames. Aims. Our aim is to refine the LQAC-6 catalogue in order to compile a selection of quasars with properties suitable for an extension of future celestial reference frames and to establish a comprehensive catalogue of AGNs that will enable the statistical study of their properties on a large scale. Methods. Following an analysis of the objects responsible for the most significant anisotropy in the LQAC-6 catalogue, we compared and evaluated several mid-infrared quasars selection criteria using a reference dataset. We applied the best criteria to remove the least probable AGNs from the initial dense region and analyse the astrometric properties of the refined catalogue. Results. Our analysis has enabled us to refine one of the most dense region in the LQAC-6 catalogue by identifying several quasar selection criteria that proved particularly effective on our test set. We then demonstrate that the objects in the refined catalogue exhibit promising statistical astrometric properties for future celestial reference frames and large-scale statistical studies of quasars.
Source: Astronomy and Astrophysics
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $1,865
OpenAlex ID: W7220435972