New multiple AGN systems with sub-arcsec separation: confirmation of candidates selected via the novel GMP method

TL;DR

This paper confirms multiple AGN systems with sub-arcsec separations using integral-field spectroscopy, doubling known cases below 7 kpc at z > 0.5, and validates the GMP method for discovering such systems.

Contribution

It presents the first spectroscopic confirmation of GMP-selected multiple AGN candidates, including a potential triple AGN, demonstrating the effectiveness of the GMP method.

Findings

Confirmed two dual AGNs with sub-arcsec separation.

Detected a possible triple or lensed dual AGN system.

Doubled the number of known multiple AGNs below 7 kpc at z > 0.5.

Abstract

The existence of multiple active galactic nuclei (AGN) at small projected distances on the sky is due to either the presence of multiple, in-spiraling SMBHs, or to gravitational lensing of a single AGN. Both phenomena allow us to address important astrophysical and cosmological questions. However, few kpc-separation multiple AGN are currently known. Recently, the newly-developed Gaia Multi peak (GMP) method provided numerous new candidate members of these populations. We present spatially resolved, integral-field spectroscopy of a sample of four GMP-selected multiple AGNs candidates. In all of these systems, we detect two or more components with sub-arcsec separations. We find that two of the systems are dual AGNs, one is either an intrinsic triple or a lensed dual AGN, while the last system is a chance AGN/star alignment. Our observations double the number of confirmed multiple AGNs at projected separations below 7 kpc at z > 0.5, present the first detection of a possible triple AGN in a single galaxy at z > 0.5, and successfully test the GMP method as a novel technique to discover previously unknown multiple AGNs.