Correlation and Quasi-periodic Oscillation Analysis of Light Variation in Blazar CGRaBS J0929+5013 and J2146-1525

We used the Lomb-Scargle Periodogram (LSP) and the Weighted Wavelet Z-transform (WWZ) methods to analyze the observational data of the blazars CGRaBS J0929+5013 and J2146-1525 at the 15 GHz radio and gamma-ray bands for about 12 years. The result of analysis showed that the blazars CGRaBS J0929+5013 and J2146-1525 probably have a quasi-periodic oscillations (QPOs) of about 1435 days (3.93 years) and 1321 days (3.62 years) in the radio band, respectively, with a confidence level of >3σ (99.7%). However, the periodicity of the light curve of the gamma band is weaker. Based on the spiral jet model in the supermassive dual black hole system, the primary black holes masses M of the blazars CGRaBS J0929+5013 and J2146-1525 are estimated to be 4.3×10⁹M_⊙ and 2.7 × 10⁹M_⊙, respectively. In order to explore the origin of optical variation in radio and gamma-ray bands, we calculated the correlation between the blazar CGRaBS J0929+5013 and J2146-1525 radio and the gamma band using the discrete correlation function, and found that there is no obvious correlation between them. This result indicates that the radiation may come from different areas.