A SysTematic seaRch fOr Dual Agns in meRgINg Galaxies (ASTRO-DARING) II: first results from long-slit spectroscopic observations

TL;DR

This paper presents initial results from a systematic long-slit spectroscopic survey (ASTRO-DARING) that identified nearly 40% of observed merging galaxies as dual AGN candidates, advancing understanding of galaxy and black hole co-evolution.

Contribution

It introduces an innovative method for systematically detecting dual AGNs in merging galaxies and reports the first observational results from this approach.

Findings

16 likely dual AGNs identified

15 new dual AGN candidates discovered

Nearly 40% detection efficiency

Abstract

Building a large sample of kiloparsec (kpc)-scale dual active galactic nuclei (AGNs) amongst merging galaxies is of vital importance to understand the co-evolution between host galaxies and their central super massive black holes (SMBHs). Doing so, with just such a sample, we have developed an innovative method of systematically searching and identifying dual AGNs of amongst kpc scale merging galaxies and selected 222 candidates at redshifts $\leqslant$ 0.25. All the selected candidates have FIRST radio detection and at least one of two cores previously revealed as AGN spectroscopically. We report the first results from A SysTematic seaRch fOr Dual Agns in meRgINg Galaxies (ASTRO-DARING), which consist of spatially resolved long-slit spectroscopic observations of 41 targets selected from our merging galaxies sample carried out between November 2014 and February 2017, using the Yunnan Faint Object Spectrograph and Camera (YFOSC) mounted on the 2.4 meter telescope in Lijiang of Yunnan Observatories. Of these 16 are likely dual AGNs and 15 are newly identified. The efficiency of ASTRO-DARING is thus nearly 40 per cent. With this method, we plan to build the first even sample of more than 50 dual AGNs constructed using a consistent approach. Further analysis of the dual AGN sample shall provide vital clues for understanding the co-evolution of galaxies and SMBHs.