Potential 4.35-year quasi-periodic oscillation in \(\gamma \)-ray emission from BL Lac J0811.4\(+\)0146

Abstract

Fermi Large Area Telescope (Fermi-LAT) observations reveal a significant population of blazars, and recent astrophysical research has focused on exploring flux variations in blazars. Up to now, Fermi-LAT has discovered a significant number of blazars, displaying quasi-periodic behaviour. In this study, Fermi-LAT data is utilized to construct the \(\gamma \)-ray light curve for blazar J0811.4\(+\)0146 spanning from August 2008 to November 2024, covering 16 years of observations. Four distinct methods, namely, Lomb–Scargle periodogram (LSP), Weighted wavelet Z-transform (WWZ), discrete correlation function (DCF) and Jurkevich (JV), are employed to investigate \(\gamma \)-ray emissions from this blazar in detail. The analysis reveals quasi-periodic oscillation (QPO) behaviour with a period of \(4.35 \pm 0.34\) years. Significance of this QPO is assessed using Monte Carlo simulations, which indicate a significance level of 4.5\(\sigma \). This study suggests that the detected QPO can be plausibly explained by Newtonian-driven jet precession associated with a supermassive black hole binary system (SMBHB). Utilizing this model, we estimate, mass of the primary black hole to be \(7.3 \times 10^9 \textrm{M}_{\odot }\), mass of the secondary black hole to be \(2.1 \times 10^9 \textrm{M}_{\odot }\) and \(\frac{R_{1}}{R_{2}}\) to be 0.27, resulting in an orbital period of the secondary black hole (\(P_{M_2}\)) of 1.15 years and a precession period of the jet of \(\sim \)42.49 years.