Multiband Variability Analysis of 3C 454.3 and Implications for the Center Structure

We have analyzed the light curves of 3C 454.3 at the infrared, optical, soft X-ray (0.3-10 keV), and.-ray (0.1-300 GeV) waveband, and found the evidence of quasi-periodicity. The light curves show that 3C 454.3 is a strongly active object. A period signal of P = 210.8 +/- 12.1 days is confirmed by two methods consistently: the Lomb-Scargle periodogram and the Jurkevich method. The variations of the infrared, optical, soft X-ray, and.-ray are well correlated, which suggests that these seven band emissions originate from the same population of electrons in the jet. The multifrequency variations in the emission fluxes of 3C 454.3 may be caused by the nonballistic helical motion of emitting components in the jet, which has the precession and the helical magnetic field. Moreover, these provide some evidence for the existence of a supermassive binary black hole (SMBBH) system in the center of 3C 454.3.