2025ApJ...983...90Z

In this paper, an oversimplified model is proposed to test the effects of intrinsic active galactic nucleus (AGN) variability on expected optical quasiperiodic oscillations (QPOs) related to subparsec binary black hole systems (BBHs) in broad-line AGN. The commonly accepted continuous autoregressive process is applied to describe intrinsic AGN variability related to each BH accreting system in a subparsec BBH system. Considering obscurations related to orbital rotations with periodicity T_p, artificial light curves including signals for optical QPOs can be built. Then, comparing the intrinsic periodicities T_p with the measured robust periodicities T_o through the artificial light curves, we find distributions of T_p/T_o have four significant peaks around 1, 2, 3, and 4, leading less than half of the artificial light curves to have consistency between T_o and T_p. Moreover, different collected model parameters have few effects on the distributions of T_p/T_o, indicating the effects of intrinsic AGN variability on optical QPOs are significantly strong and stable. Furthermore, after checking properties of optical QPOs in the light curves with different time steps, we find there are tiny effects of time steps on optical QPOs.