Oscillatory patterns in the light curves of 5 long-term monitored type 1 AGN

TL;DR

This study detects and analyzes oscillatory patterns in the long-term light curves of five type 1 AGN using a novel hybrid method, revealing different dynamical regimes and potential physical mechanisms behind the observed periodicities.

Contribution

It introduces a new hybrid analytical method for detecting oscillations in AGN light curves and demonstrates its effectiveness on five well-known objects, revealing diverse dynamical behaviors.

Findings

Periodic variations found in 3C 390.3, NGC 4151, NGC 5548, E1821+643

Different dynamical regimes identified in NGC 5548 and E1821+643

Absence of oscillations in Arp 102B linked to weak coupling

Abstract

A new combined data of 5 well known type 1 AGN are probed with a novel hybrid method in a search for oscillatory behavior. Additional analysis of artificial light curves obtained from the coupled oscillatory models gives confirmation for detected periods that could have physical background. We find periodic variations in the long-term light curves of 3C 390.3, NGC 4151, NGC 5548 and E1821+643, with correlation coefficients larger than 0.6. We show that oscillatory patterns of two binary black hole candidates NGC 5548 and E1821+643 corresponds to qualitatively different dynamical regimes of chaos and stability, respectively. We demonstrate that absence of oscillatory patterns in Arp 102B could be due to a weak coupling between oscillatory mechanisms. This is the first good evidence that 3C 390.3 and Arp 102B, categorized as double-peaked Balmer line objects, have qualitative different dynamics. Our analysis shows a novelty in the oscillatory dynamical patterns of the light curves of these type 1 AGN.