Some Statistical Study Of Fermi Blazar Light Curve

The current paradigm,or working model, for the AGN phenomenon is a ’central engine’ that consists of a hot accretion disk surrounding a su-permassive black hole. There is a relativistic jet on each side of the accretion disk, which emit almost each band of radiation.The gravitational energy is transformed into radiant energy while the black hole is accreting the mater around. In the falling process the accreting disk is constructed since the falling matter with angular moment, and several bounds of radiation, such as optical, ultraviolet,x-raysand other wavelengths are emitted. Blazars is one of the most extreme classes of AGNs, which have high luminosity, large-amplitude and rapid variation,high and variable polarization,radio-dominance,superluminal motion,and all electromagnetic band nonthermal radiation process.The Blazars’ variability is extremely complicated ,which has different timescale and different variable amplitude. Its variability is linked to the inner structure and mechanism of the object. For such complex changes,it is necessary to use qualitative and quantitative statistical methods. It is a meaningful job to research the type of variability. A vast amount of ob-servational data has been obtained about the variability of blazars. Many cases of periodic variability have been found from the light curves of blazars From another point of view, the data also shows that blazar light curves are similar to the "red noise" in the frequency domain Therefore, what type of the "red noise" is it? In this work, A simple model of the "red noise"is the Brownian or random walk noise, which can be produced by integrat-ing the white noise, is used to test whether the light curve of the Blazars object is similar to that. Firstly,we use the K - S test to compare the nor-malized daily variability of flux of 130 sources with gaussian distribution.The test results show that the distribution of the daily variation of gamma-ray emission is not equivalent to a Gaussian distribution. The variability of gamma-ray emission of some Fermi blazars should not be considered as being produced only by integrating a finite number of random emission events. Perhaps it is the connection with some internal physical mechanism instead. Secondly, we make the K-S test for the daily variability distribu-tions of any pair of sources, the distributions of some pairs of sources are found to be very similar. Also their distributions are different from Gaussian distributions. Maybe some similar physical mechanism can produce these variations.Thirdly since the distribution of daily variability does not follow a Gaussian distribution, Thirdly some parameters of the distribution should be checked. We found that the distribution of negative variability is slightly flatter than that of positive one.This indicates that the negative part of the dispersion is larger than the positive part.That is, the negative part of the scale of the flow changes when the scale is small, and the positive part of the scale of the basic changes in the flow of almost .Fourthly we calculate the skewness and kurtosis . The kurtosis is found to increase with increasing skewness.