振荡吸积盘的光变研究

理论研究指出随机振荡吸积盘可能引起活动天体的光变,然而观测数据分析表明光变中除了含有随机噪声外还存在混沌因素.将混沌因素引入到随机振荡吸积盘中,构成"混沌+随机"振荡吸积盘模型.通过分析扰动的相图,直观再现了混沌吸引子的状态.研究结果表明:在随机因素占主导时,光变混乱无序;随机因素与混沌因素相当时,光变上下起伏类似于心电图;混沌因素占主导时,光变具有一定有序性.模拟光变曲线的关联维与观测数据的关联维一致,表明模拟光变曲线与观测结果之间存在内在联系.

Research on the optical variability of oscillating disk

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.
Keywords： black hole system accretion disk chaos optical variability