Research The Quasiperiodicity Of Multi-bands Variability Of Blazars

The variabilities are important features of Fermi blazars.The observed multiwavelength variabilities of many sources show some kind of periodicity.The main content of this paper is Blazar periodic analysis of the light variation curve and detect the possible quasi-periodic light variation.We introduced how to use Fermitools to analysis the γ-ray data from Fermi-LAT Space Telescope first.Use aperture photometry and likelihood analysis to get the γ-ray light curves.The LSP method,Independent frequency calculation,epoch-folding method,and red noise fitting method are introduced and derived in detail.The derivation of the modifiers of independent frequencies complements the problem of generating false signals in the periodic calculation of time intervals of inhomogeneous observation data.Finally,the LSP method,DACF,Jurkevich,REDFIT38,WWZ method,red noise fitting and the independent frequency calculation is used to analyze the quasi-periodic of light curves of 3FGL J0449.4-4350 and B3 0307+380,And estimated the confidence.Our first work is the radio variability analysis of the FSRQ B3 0307+380.B3 0307+380 is a FSRQ that have radio light curves.It data comes from the OVRO.In order to calculate the doppler factor of radio band,We used double exponential function to fit 12 complete explosion processes in B3 0307+380.The doppler factor Distribution are 8.6~30.5,Average of doppler factor is 8.3±4.9(sd).This result indicate that the radio emission is strongly beamed,and it is consistent with the wellknown relativistic jet model.Our second work is the γ-ray light curves analysis of BL Lac 3FGL J0449.4-4350.3FGL J0449.4-4350 is a TeV BL Lac in Fermi LAT 4-year Source Catalog.We have assembled the historical light curves of the BL Lac Object 3FGL J0449.4-4350 at optical and γ-ray bands,analyzed the periodic variability of the light curves.We detected a marginally possible quasi-periodic oscillation of ～450 days.assuming the QPO come from the helical motion of jet,The black hole mass M=7.7*109M⊙is adoped.To explore the origin of the γ-ray,we investigated the optical-γ-ray correlations using discrete correlation function method,and found that the correlation between the two bands is very significant.This strong correlation tends to imply lepton self-synchro-Compton model to produce the γ-ray.