耀变体的光变特性分析和光变模型研究

发布时间：2018-04-12 17:18

本文选题：耀变体 + 光变　；参考：《云南师范大学》2015年硕士论文

【摘要】：耀变体是宇宙中最剧烈的活动现象之一。由于耀变体活动与星系中心的超大质量黑洞有联系,因此,耀变体光变数据分析和光变模型建立对解决星系中心超大质量黑洞的吸积与喷流过程有重要作用。论文利用卡方评价方法和Lomb-Scargl算法研究了S5 0716+714的周期特性,并从数学角度简要对比这两种算法的异同。得到光变周期后,利用全局热吸积盘理论估计S5 0716+714的中心黑洞质量,对影响黑洞质量的粘滞系数和多普勒因子做相应讨论。研究表明AGN的光变可能是一种非线性现象,我们采用现代数学中的分形理论、关联维和相空间方法继续研究观测数据,并定量表征了光曲线的混沌特性。研究结果表明,耀变体S5 0716+714的中心黑洞是一个受到各种噪声影响的低维混沌系统。为从理论上验证上述研究结果,我们基于Harko等人建立的随机振荡吸积盘模型,通过常数变易法求解了郎之万微分方程在过阻尼、临界阻尼和小阻尼三种情况下的解析解,并对模拟光曲线的功率谱密度进行了研究,指出尽管这种吸积盘模型可以获得较大范围的功率谱密度,但是在形貌上模拟光变曲线与真实观测数据却存在较大差异。作为改进,我们结合本文的数据分析结果,引入混沌因素,构造了“混沌+随机”振荡吸积盘模型,分别给出混沌因素占优、混沌与随机因素相当、随机因素占优三种情况下的模拟光变曲线,最后所得的模拟光变曲线与观测数据不仅在形貌上非常相似,而且在混沌分析方法下,二者的关联维几乎一致。本文所构造的“混沌+随机”振荡吸积盘模型比Harko等人的随机振荡吸积盘模型更接近于实际观测。
[Abstract]:It is one of the most violent phenomena in the universe.Because the activity of the supermassive black hole in the center of the galaxy is related to the activity of the glowing body, the analysis of the light variation data and the establishment of the light variation model play an important role in solving the accretion and jet process of the supermassive black hole in the center of the galaxy.In this paper, the periodic characteristics of S5 0716 714 are studied by chi-square evaluation method and Lomb-Scargl algorithm, and the similarities and differences between the two algorithms are compared from the point of view of mathematics.The global thermal accretion disk theory is used to estimate the mass of the central black hole of S5 0716 714. The viscosity coefficient and Doppler factor affecting the mass of the black hole are discussed.The study shows that the photovariation of AGN may be a nonlinear phenomenon. We use the fractal theory in modern mathematics, correlation and phase space methods to continue to study the observed data, and quantitatively characterize the chaotic characteristics of the optical curve.The results show that the central black hole of S5 0716 714 is a low-dimensional chaotic system affected by various noises.In order to verify the above results theoretically, based on the stochastic oscillating accretion disk model established by Harko et al, we solve the analytic solutions of Langzhiwan differential equation under three cases of overdamping, critical damping and small damping by constant variable method.The power spectral density of the simulated optical curve is studied. It is pointed out that although the accretion disk model can obtain a large range of power spectral density, there is a great difference between the simulated optical curve and the real observed data in morphology.As an improvement, we combine the data analysis results of this paper and introduce chaotic factors to construct the chaotic random oscillating accretion disk model. The chaotic factors are dominant, and the chaos is the same as the random factors.At last, the simulated phototropic curve is very similar to the observed data, and the correlation dimension of the two curves is almost the same under the chaotic analysis method.The chaotic random oscillatory accretion disk model constructed in this paper is closer to the actual observation than that of Harko et al.
【学位授予单位】：云南师范大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P145.8;P157

【共引文献】