The Detection of Possible γ-Ray Quasi-periodic Modulation with ∼600 days from the Blazar S2 0109+22

Abstract In this work, we analyzed the long-term γ -ray data by a Fermi Large Area Telescope of blazar S2 0109+22, ranging from 2008 to 2023. The quasi-periodic oscillations (QPOs) blazars aided in investigating physical properties internal supermassive black holes, nature variability, and underlying radiation mechanism. We employed four different methods—Weighted Wavelet Z-transform, Lomb–Scargle periodogram, REDFIT phase folded light curve analysis, for searching QPO signals. Our analysis identified possible behavior with periodicity ∼600 days 2013 November–2023 January at significance level ∼3.5 σ . This signal sustained ∼9 yr, corresponding 5.6 cycles, which was good agreement previously observed ∼657 radio. explained phenomenon based on accretion model lighthouse effect, binary hole system.