Computing the Period of Light Variability in BL Lac Objects Using the Weight Wavelet Z-transform
Xun Yun-bin · Journal of Yunnan Normal University · 2013
A method based on the principle of wave analysis called the Weighted Wavelet Z-transform(WWZ) is presented for finding the period of light variation in BL Lac objects.All available optical data of ON 231 and OJ 287 are collected in this paper,and the long-term curves of ON 231 and OJ 287 are presented.With the WWZ method,The authors find the long periods light variability in the BL Lac objects ON 231 and OJ 287,which of ON 231 are 13.70 and 6.85 yr,of OJ 287 is 11.42 yr.Analysis and computing have shown that Weighted wavelet Z-transform is very suitable for handling non-interval data,it have addressed that the discrete wavelet transform can not handle the problem of non-interval data,and can effectively remove the boundary effect.