Study On The Variation Of Blazar

There are two subclasses of blazars,namely,flat spectrum radio quasars（FSRQs）and BL Lacs.Blazars surface some of the extreme observed properties,such as large amplitude and fast variability behavior,high polarization,non-thermal continuous radiation,and apparent super-luminal phenomena.Variability is one of the main observational characteristics of blazar.It is generally believed that these rapid variation behaviors are caused by the continuous radia-tion produced by relativistic jets.Therefore,the variation of blazar is to reveal active galactic nuclei（AGN）.One of the effective means of observing properties.The amplitude,time-scale,energy spectrum distribution and radiation region of multi-wavelength size,location,jet struc-ture,shape,and dense objects in the central region are closely related.Also,as an extragalactic high energy radiation source,combined with multi-wavelength observation to carry out optical band observation research on blazar.To the extragalactic high energy radiation source,high energy Cosmic rays and the ultimate destination of galaxy evolution are important references.The paper is divided into six chapters.The first chapter is the introduction,which mainly describes the observation characteristics and classification of AGN as well as the radiation mech-anism and theoretical model.The second chapter is about multi-wavelength observation and data,mainly introduces observation equipment,long-term observation of optical telescope,data processing process and analysis method.The chapter 3 and 4 introduces the main work during the doctoral period,which is the optical study of an Te V blazar and a Quasar,respectively.In chapter 5,the quasi-periodic variation of gamma-ray band of gamma-noise blazar is introduced.The sixth chapter is the summary and discussion of the whole paper.In our work,we used a 70cm optical telescope at Georgia Abastumani Observatory on Long-term optical R-band observations of two Te V blazar FSRQ 3C 454.3 and BL Lac 1ES 2344+514have been performed The Fermi-LAT gamma-ray band observations of FSRQ S5 1044+71 for 12years were analyzed.Based on the For optical data of 3C 454.3 and 1ES 2344+514,we discuss their short-time scale and long-time scale optical aberration For S5 1044+71,we analyze the Fermi-LAT light curve of 12 years,whether there is quasi-periodic variation（QPOs）,and the following main results are obtained:For 3C 454.3,we find that there are 10 flare peaks and variation within an intraday variabilities（IDV）and the maximum variation isΔR=3.825 mag.The results of periodic analysis indicate that a light curve may exist The quasi-periodic components are:p=3.04±0.02 yr,P=1.66±0.06yr and P=1.20±0.03 yr.For the period p=3.04±0.02 yr found in 3C 454.3,the accretion disk model and dual jet flow model are used In the accretion disk model,we get the black hole mass M=1.17×10⁹M_⊙,and the orbit radius r=2.77×10¹⁶cm.For the lighthouse model,we used two jet with two Doppler beaming components to fit the observed light curve.The optical band of Te V blazar 1ES 2344+514 is relatively stable,and the maximum mag-nitude change isΔR=1.154 mag.In 628 observation nights,we found only once amplitude ofΔR=0.155 mag over the timescale of optical variability isΔT=12.99 minutes within a day.According to the Kelvin-Helmholtz instability principle,if the magnetic field（B）is greater than a critical value B_c.It will reduce the incidence of IDV in the light curve.Our results meet well with this principle.At the same time,a one-zone Synchronous Self-Compton model（SSC）was used to calculate its energy spectrum The SED is fitted to obtain the physical parameters in the radiation region.In addition,three different period analysis methods were used to obtain the period of 4 years were p=2.72±0.47 yr,P=1.61±0.18 yr and P=1.31±0.13yr,respectively.When we consider that the central region of the source is a binary black hole system,citing the period p=2.72±0.47 yr.the orbital radius of the binary black hole sys-tem is obtained as r=7.18×10¹⁶cm.Further,we estimate binary black holes The lifetimeτ=6.24×10²yr.S5 1044+71 was found to have a quasi-period with a high confidence of P=3.04±0.02 yr.We also consider introducing The periodic variation of the initial flux is caused by a binary black hole system in the center of the source.We use the double jet model to simulate The distributions of Doppler factor and apparent superluminal factors are 5<δ<18,and 7.55<β_app<20.53,respectively.At the same,we also obtained the black hole mass M=1.45×10⁹M_⊙of this source,and the orbit radius is r=2.14×10¹⁶cm.