Blazar的短时标光变和射电长时标光变研究

【作者】 兰花艳；

【导师】 马力；

【作者基本信息】 云南师范大学 ， 天体物理， 2008， 硕士

【摘要】 活动星系核(AGNs)是当代天体物理学研究的热门课题之一,Blazar天体是AGNs中具有极端物理性质的一个子类,它以高亮度、大振幅快速光变、高且变化的偏振、射电核主导、视超光速运动、全波段非热辐射为主要特征。由于其特殊的性质,Blazar天体为探测AGNs中心区域的性质和研究能量从中心黑洞释放提供了重要机会。Blazar天体能量的产生、喷流的形成和加速问题的研究对中心黑洞的认识非常重要,其中Blazar天体光变的研究对探索AGNs内部物理结构、辐射机制等信息有重要意义。本文系统阐述了Blazar天体的观测特征、多波段能谱特征、辐射理论模型、短时标光变特征。分析研究了已观测到的五个X射线选BL Lac天体的光变曲线特征以及射电源的射电光变特征。主要介绍了短时标光变的定义,并对Blazar天体的短时标光变特征作了分析总结,同时还搜集了46个(来自27篇参考文献)具有短时标光变的Blazar天体,利用OJ287和S50716+714的光变曲线验证了短时标光变的部分特征；并且总结出了BL Lac天体在高态和低态的短时标光变的差异。同时,论文还搜集了射电源的射电光变的一些数据,并给出了解释射电波段光变的理论模型,还在4.8GHz、8.0GHz和14.5GHz对168个Blazar天体的长周期光变及光变参数进行了统计分析,为Blazar天体的研究提供了更多信息。更多还原

【Abstract】 Active Galactic Nucleus (AGNs) is one of the hottest researches in modern astrophysics. Blazars is one of the most extreme classes of AGNs, which have high luminosity, large-amplitude and rapid variation, high and variable polarization, radio core-dominance, superluminal motion, and all electromagnetic band nonthermal radiation process. Because of their special nature, blazars provide important opportunities for detecting the central region of the AGNs and studying energy that release from the central black hole. It is significant for knowledgement of the central black hole to research for energy generation, jets form and the issue of acceleration. Variability is an important parameter, play an important role in surveying the inner physical structure and radiation mechanism of blazars.In this paper, we illuminate observation features, spectral energy distributions, theoretical radiation model and features of short-timescale variability of blazars, and analyze characteristics of the light curves of five X-ray selected from BL Lac objects that were observed and radio variability for radio sources. After introducing primanly the definition of short-timescale variability, we study and summarize characteristics of short-timescale veriability, meanwhile collect 46 blazars which have short-timescale variability (got from 27 referenes), and verify some features of short-timescale variability from light curves of OJ287 and S50716+714. Then we obtain differences of short-timescale variability between high state and low state of BL Lacs. Additionally, collecting several data about radio variability of radio source, we give the theory models that can explain the radio variability. We also provide more informationes for blazars reseach after analyzing statistically the long-term variability and variability parameter for 168 radio sources are statistically analysed in 4.8GHz, 8.0GHz and 14.5GHz.更多还原