Line Shapes Emitted from Spiral Structures around Symmetric Orbits of Supermassive Binary Black Holes

TL;DR

This paper models how supermassive binary black holes influence the emission line profiles of active galactic nuclei, providing insights into their variability and observational signatures.

Contribution

It introduces a detailed model of emission line variability caused by supermassive binary black holes in AGN, considering different orbital parameters and inclinations.

Findings

Emission line flux and shapes vary with SMBBH orbital parameters.

Inclination affects the observed emission line profiles.

Variability patterns can indicate the presence of SMBBH systems.

Abstract

Variability of active galactic nuclei is not well understood. One possible explanation is existence of supermassive binary black holes (SMBBH) in their centres. It is expected that major mergers are common in the Universe. It is expected that each supermassive black hole of every galaxy eventually finish as a SMBBH system in the core of newly formed galaxy. Here we model the emission line profiles of active galactic nuclei (AGN) assuming that the flux and emission line shapes variation are induced by supermassive binary black hole systems (SMBBH). We assume that accreting gas inside of circumbinary (CB) disk is photo ionized by mini accretion disk emission around each SMBBH. We calculate variations of emission line flux, shifts and shapes for different parameters of SMBBH orbits. We consider cases with different masses and inclinations for circular orbits and measure the effect to the shape of emission line profiles and flux variability.