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

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.

13 pages, 13 figures, 6tables, A&A accepted

References in corpus (16)

• The Sloan Digital Sky Survey Quasar Catalog: Sixteenth Data Release
• A Compact Supermassive Binary Black Hole System
• A possible close supermassive black-hole binary in a quasar with optical periodicity
• unWISE: unblurred coadds of the WISE imaging
• The CatWISE2020 Catalog
• The 2dF-SDSS LRG and QSO Survey: The spectroscopic QSO catalogue
• The Formation and Gravitational-Wave Detection of Massive Stellar Black-Hole Binaries
• Unveiling the nature of INTEGRAL objects through optical spectroscopy. VII. Identification of 20 Galactic and extragalactic hard X-ray sources
• Quasar and galaxy classification in Gaia Data Release 2
• Searching for Binary Supermassive Black Holes via Variable Broad Emission Line Shifts: Low Binary Fraction
• Finding Quasars behind the Galactic Plane. I. Candidate Selections with Transfer Learning
• New multiple AGN systems with sub-arcsec separation: confirmation of candidates selected via the novel GMP method
• Improving the reliability of photometric redshift with machine learning
• QSO photometric redshifts using machine learning and neural networks
• PhotoRedshift-MML: a multimodal machine learning method for estimating photometric redshifts of quasars
• SQUAB I: The first release of Strange QUasar candidates with ABnormal astrometric characteristics from Gaia EDR3 and SDSS