Study On Optical Variable Characteristic Analysis And Light Variable Model

Blazar is one of the most violent events in the universe phenomenon. Because of blazars and supermassive black holes which in galactic center are related, therefore,light curves variable data analysis and variable model for solving the accretion and jet process of supermassive black hole plays an important role.In this paper, we analyze the period feature of S5 0716+714 by using chi-square evaluation methodology and Lomb-Scargle algorithm. Then we briefly compare these two algorithms from a mathematical point view. After obtained the light curve period,we estimate the central black hole mass of S5 0716+714 by using global hot accretion disk theory, and discuss the viscosity coefficient and the Doppler factor. There have been many studies shown that AGN variable may be a non-linear phenomenon. We quantificationally analyze the chaotic feature of the light curve by using modern mathematical theory: fractal theory, correlation dimension and the phase pattern. This results point that the central black hole is a low dimensional chaotic system under the influence of various noise.To verify these findings in theory, we detailedly study the stochastic oscillations of accretion disk which formulated in terms of a Langevin type differential equation.By using the method of variation of constants, the Langevin type equation can be solved for three cases(large, critical, and small damping).The luminosity and power spectral density(PSD) also be calculated. This accretion disk model can get a wide range of power spectral density, but simulate light curve and the real data has a big difference in appearance. As an improvement, we combine the data analysis in the foregoing, introduce chaos factor, and construct "Chaotic + Stochastic" oscillating accretion disk model. Light curves for three cases(Chaos dominant, Stochastic dominant, and Equal factor) are calculated. After adding the chaotic factor, the simulated light curve is very similar with observational data in appearance, and both have the same correlation dimension by using chaos analysis method. In our paper,the "Chaotic + Stochastic" oscillating accretion disk is better than stochastic oscillating accretion disk.