A Possible 3-Year Quasi-Periodic Oscillation in {\gamma}-Ray Emission from the FSRQ S5 1044+71

TL;DR

This study analyzes over 12 years of Fermi LAT gamma-ray data from S5 1044+71, identifying a potential 3-year quasi-periodic oscillation, and discusses a binary black hole model as a possible cause.

Contribution

First detection of a 3-year quasi-periodic oscillation in gamma-ray emission from S5 1044+71 using multiple analysis methods, suggesting a binary supermassive black hole presence.

Findings

Possible 3.06-year QPO with 3.6σ significance

Binary black hole model explains the variability

Estimated jet Doppler factors and velocities

Abstract

Variability is a typical observation feature of Fermi blazars, sometimes it shows quasi-periodic oscillation (QPO). In this work, we obtained 5-day binned light curves (with a time coverage of $\sim$ 12.9 yr) for S5 1044+71 based on Fermi LAT data, adopted five different methods: Date-compensated Discrete Fourier Transform (DCDFT), Jurkevich (JV), Lomb-Scargle Periodogram (LSP), a Fortran 90 program (REDFIT) and the Weighted Wavelet Z-transform (WWZ) to the $\gamma$-ray light curve, and found a possible QPO of 3.06 $\pm$ 0.43 yr at the significance level of $\sim3.6\sigma$. A binary black hole model including accretion model and dual-jets model is used to explain this quasi-periodic variability. We also estimated the Doppler factors and the apparent velocity for the two jet components. We speculate that this $\gamma$-ray quasi-periodic modulation suggest the presence of a binary supermassive black hole in S5 1044+71.