Analysis of Optical Property of BL Lac Object CGRaBS J0141-0928

Observation data from the Owens Valley Radio Observatory (OVRO) 40-meter telescope showed multiple dramatic light variations in the 15 GHz radio band of the blazar CGRaBS J0141-0928. LSP (Lomb-Scargle-Periodogram) method, WWZ method (Weighted Wavelet Z-transform, WWZ) and Jurkevich method are used to analyze the light variable period of CGRaBS J0141-0928. The results show that the object has a light variable period of about 649 days (4.4σ significance level), and its Quasi-Periodic Oscillation (QPO) may be caused by the helical motion of the jet. The brightness temperature, time scale of light variability and Doppler factor are estimated by fitting the processes of two bursts with double exponential function. The Doppler factor estimated by the optical time scale of variability is 3.8, and the results show that CGRaBS J0141-0928 has a significant beaming effect in the radio radiation band. The DCF (Discrete Correlation Function) method is used to analyze the correlation between the radio band and Gamma-ray and optical R band. It is found that there is a strong correlation between optical light variability and radio light variability, and the optical light variability is 66 ± 40 days ahead of the radio variability.