基于经验模态分解的OJ287光变周期分析

The Variability Periodicity Analysis of Blazar Object OJ 287 Based on Empirical Mode Decomposition

针对传统周期分析方法的不足,应用处理非线性、非平稳信号的经验模态分解(Empirical Mode Decomposition,EMD)方法对Blazar天体OJ 287从1891年到2010年的光学V波段流量进行了多时间尺度分析,获得了10个代表不同时间尺度的本征模态函数(Intrinsic Mode Function,IMF)分量和1个趋势项.研究结果表明,OJ 287光学V波段流量的主要光变周期是12.34 yr,方差贡献率也以12.34 yr的为最大,证实了OJ287光学V波段具有长光变周期12.34 yr,且平均流量随时间呈递减的趋势.

Aiming at the shortage of the classical methods in the periodicity analysis, the method of empirical mode decomposition （EMD） as a nonlinear and nonsteady signal processing method is applied to the flux of OJ 287 in the V band from 1891 to 2010, and 10 intrinsic mode functions and one residual function are obtained from the light curves. The results show that there is a period of 12.34 yr in the light variation of the flux of OJ 287 in the V band, and its variance contribution is the largest. This result has confirmed that there is the long-period light variability of 12.34 yr for the outbursts in OJ 287. The residual function is depressed.