Wavelet Analysis of the Variability Periodicity Data of Quasar 3C 345
F. Dong, H. J. Zhang, Lisheng Mao, X. Zhang, Yi Zheng, L. Tang · Acta Astronomica Sinica · 2010
A new method to analyze unevenly spaced data is described,which is based on the principle of wavelet analysis called the Weighted Wavelet Z-transform(WWZ).All available optical B-band data of quasar 3C 345 from more than 100 years are collected in this paper,and the long-term light curves of 3C 345 are presented.With the WWZ method, the data between the years of 1965 to 1992 are analyzed.The results show that there are 3 periodic components in the data.Based on our analysis,the periodicity of T=4.54～5.23 yr and T=9.59～11.51 yr is steady,while T=624～941 d is not a steady period.