Research on the optical variability of oscillating disk

Abstract

Theoretical study shows that stochastic oscillations of an accretion disk should induce the variability of active objects, however, observations indicate that it contains both chaotic factor and random noise. We develop a “chaotic + stochastic” oscillating accretion disk model for the variability. In this model, the chaotic factor is introduced into the oscillating accretion disk, and the chaotic attractor is reproduced through analyzing the phase pattern of disturbance. Results show that: when the random factor dominates the variability, the light curve exhibits a strong randomness; when the random factor is equal to the chaotic factor, the light curve shows a “heartbeat” which is similar to an electrocardiogram; when the chaotic factor dominates the variability, the light curve shows a certain orderliness. The correlated dimension of the simulated light curve is consistent with the correlated dimension of observational data. This suggests that there is an intrinsic relationship between the simulated light curve and observational data.