DULAG: A DUal and Lensed AGN candidate catalog with GMP method

TL;DR

This paper introduces DULAG, a new catalog of dual and lensed AGN candidates identified using the Gaia GMP method, significantly expanding the known sample with high reliability and providing insights into AGN properties.

Contribution

The study develops a reliable dual and lensed AGN candidate catalog from Gaia data, using optimized selection criteria based on property differences, and identifies new dual AGN and lensed systems.

Findings

DULAG catalog contains 5,286 sources with 1,867 highly reliable candidates.

37 sources in the Golden sample are dual or lensed AGN.

Identification of three close AGN pair candidates.

Abstract

Context. A series of studies have demonstrated that the Gaia multipeak method (GMP) is a very efficient technique to select active galactic nucleus (AGN) pair candidates. The number of candidates is determined by the size of the input AGN catalogs, usually limited to spectroscopically-confirmed objects. Aims. The objective of this work is to compile a larger and highly reliable catalog of GMP pair candidates extracted from the six million objects the Gaia AGN catalog, the majority of which lack spectroscopic information. Methods. In order to ascertain the differences in the properties of GMP pair candidates compared to normal AGN, we conducted an investigation utilising samples of GMP AGN. These differences were employed to establish the optimal selecting criteria, which ultimately led to the identification of a highly reliable candidate catalog. Results. We found significant differences in astrometry and multi-band colour distribution between normal AGN and GMP pair candidates. A DUal and Lensed AGN candidate catalog with GMP method (DULAG) comprising 5,286 sources was ultimately compiled, accompanied by a highly reliable Golden sample of 1,867 sources. A total of 37 sources in the Golden sample have been identified as dual AGN or lensed AGN. For the majority of sources in the Golden sample, we provide reference redshifts and find three close AGN pair candidates among them.