Detection of quasi‐periodic oscillations in γ ‐ray and optical light curves of the BL Lac 4FGL J0650 .7 + 2503

In this work, we have assembled the long‐term variability data of the blazar 4FGL J0650.7 + 2503 in the γ‐ray and the optical bands, spanning about 11.9 and 8.6 years, respectively. The light curves are then analyzed by using Lomb‐Scargle Periodogram, Weighted Wavelet Z‐transform, Jurkevich and discrete correlation function techniques, and the results reveal two possible timescales of quasi‐periodic oscillation: 500 ± 37 days for γ‐ray and 330 ± 20 days for optical. To explore the origin of the γ‐ray, we investigated between the optical and γ‐ray band correlations, and found that the correlation between the two bands is very significant. This correlation can be reasonably explained by the lepton self‐synchro‐Compton model. Based on the supermassive binary black hole system model, we estimate the primary black hole mass .