We use cookies to ensure that we give you the best experience on our website. By continuing to browse this repository, you give consent for essential cookies to be used. You can read more about our Privacy and Cookie Policy.

Durham Research Online
You are in:

The abundances and properties of Dual AGN and their host galaxies in the EAGLE simulations.

Rosas-Guevara, Yetli M. and Bower, Richard G. and McAlpine, Stuart and Bonoli, Silvia and Tissera, Patricia B. (2019) 'The abundances and properties of Dual AGN and their host galaxies in the EAGLE simulations.', Monthly notices of the Royal Astronomical Society., 483 (2). pp. 2712-2720.


We look into the abundance of Dual AGN (active galactic nucleus) in the largest hydrodynamical simulation from the Evolution and Assembly of GaLaxies and their Environment (EAGLE) project. We define a Dual AGN as two active black holes (BHs) with a separation below 30 kpc. We find that only 1 per cent of AGN with LHX ≥ 1042 erg s−1 are part of a Dual AGN system at z = 0.8–1. During the evolution of a typical binary BH system, the rapid variability of the hard X-ray luminosity on Myr time-scales severely limits the detectability of Dual AGN. To quantify this effect, we calculate a probability of detection, ton/t30, where t30 is the time in which the two BHs are separated at distances below 30 kpc and ton, the time that both AGNs are visible (e.g. when both AGNs have LHX ≥ 1042 erg s−1) in this period. We find that the average fraction of visible Dual systems is 3 per cent. The visible Dual AGN distribution as a function of BH separation presents a pronounced peak at ∼20 kpc that can be understood as a result of the rapid orbital decay of the host galaxies after their first encounter. We also find that 75 per cent of the host galaxies have recently undergone or are undergoing a merger with stellar mass ratio ≥0.1. Finally, we find that the fraction of visible Dual AGN increases with redshift as found in observations.

Item Type:Article
Full text:(VoR) Version of Record
Download PDF
Publisher Web site:
Publisher statement:© 2019 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society.
Date accepted:23 November 2019
Date deposited:12 March 2019
Date of first online publication:30 November 2018
Date first made open access:12 March 2019

Save or Share this output

Look up in GoogleScholar