Mrk421的光变研究

发布时间：2018-02-24 09:34

本文关键词： Mrk421 数据处理光变光变周期双黑洞　出处：《山东大学》2013年硕士论文　论文类型：学位论文

【摘要】：自20世纪60年代类星体(Quasi-Stellar Objects, QSOs)和blazar天体等活动星系核(Active Galactic Nuclei, AGNs)发现以来,AGN的研究一直是天体物理学中最活跃的研究领域之一。AGN的研究,在能量产生、辐射机制和宇宙学等基本问题上占有重要地位。Blazar天体是AGN中最活跃的子类,具有大幅、快速光变等特征。观测和研究blazar天体的光变是获得该类天体有关特性的一种重要的手段。Mrk421是目前已知的最近的blazar天体之一,由于其同步辐射峰频高于0.1keV,它被归类为高峰频blazar (High Frequency Peaked Blazar. HBL)天体。研究Mrk421的光变特性对(?)blazar等AGN天体的研究及物理模型的建立都具有重要意义。山东大学威海天文台1.0米望远镜自2009年起便对Mrk421进行了较为细致的观测。由于数据量大,作者以NASA天文包为基础编写了时序测光数据的1DL自动处理程序,使得数据处理过程自动化程度大大提高,处理的效率得到很大提升。测试表明,该IDL程序的测光结果与IRAF的测光结果一致。作者对山东大学威海天文台1.0米望远镜Mrk421的R和V波段的观测数据进行了处理,在40个观测夜中,有39个观测夜至少有一个波段观测数据点超过了5个。作者使用C检验和F检验对这39个观测夜的数据进行了微光变的分析,未探测到微光变。前人的观测认为HBL天体与低峰频blazar (Low Frequency Peaked Blazar, LBL)天体相比,有着更少的光变,作者的结果支持这种观点。HBL天体中有着比LBL天体更强的磁场(Romeroet a1.,1999)可能是该现象产生的原因。作者从文献中搜集了Mrk421B和V波段的历史数据,并汇集了美国变星观测者协会(AAVSO)数据库及美国Arizona大学Steward天文台对Mrk421的观测数据,与山东大学威海天文台观测的V波段的数据一起,得到了Mrk421的长期光变曲线。作者使用离散相关函数和结构函数两种方法对Mrk421的光变曲线进行了周期分析,结果显示Mrk421很可能存在一个1.37年的光变周期。这可能暗示着Mrk421-中心存在密近的双黑洞系统,其中主黑洞质量为1.66×108M。,次黑洞质量为6.96×104M。作者分析Mrk421的色指数变化,包括准同时性的V-R色指数和长期的B-V色指数。分析发现在Mrk421处于低态的情况下,Mrk421表现出“变暗变红”的现象,这一现象的产生可能是由宿主星系热辐射的贡献在目标较暗时所占更大的比重导致的。
[Abstract]:Since the discovery of Quasi-Stellar objects (QSOs) and active Galactic Nuclei (AGNs) in 1960s, the study of AGNs has been one of the most active research fields in astrophysics. The Blazar object is the most active subclass in AGN, and has a large size. The observation and study of the photovariation of blazar objects is an important means of obtaining the properties of these objects. Mrk421 is one of the most recent known blazar objects. Because its peak frequency of synchrotron radiation is higher than 0.1 Kev, it is classified as blazar High Frequency Peaked Blazar.HBL. The study of AGN objects such as blazar and the establishment of physical models are of great significance. The 1.0-meter telescope of Weihai Observatory of Shandong University has made a detailed observation of Mrk421 since 2009. Due to the large amount of data, the author has compiled a 1DL automatic processing program for time series photometric data based on the NASA astronomical package. The automation degree of the data processing process is greatly improved and the processing efficiency is greatly improved. The test results show that the photometric results of the IDL program are consistent with those of the IRAF program. The authors have processed the R and V band observations of the 1.0-meter telescope at Weihai Observatory, Shandong University, in 40 observation nights. In 39 observation nights, at least one band observation data point is more than 5. The authors used C test and F test to analyze the data of these 39 observation nights. No low light change was detected. Previous observations have shown that HBL objects have less light variability than low peak frequency blazar low Frequency Peaked Blazar objects. The author's results support this view. The fact that there is a stronger magnetic field in HBL objects than in LBL objects may be the cause of this phenomenon. The author collected the historical data of Mrk421B and V band from the literature, and compiled the AAVSO database of the American Association of variable Star observers and the Mrk421 observation data of the Steward Observatory of Arizona University in the United States. Along with the data of V band observed by Weihai Observatory of Shandong University, the long term optical variation curve of Mrk421 is obtained. The authors use discrete correlation function and structure function to analyze the optical variation curve of Mrk421 periodically. The results show that there is probably a 1.37 year optical variation period in Mrk421, which may imply that there exists a close double black hole system in the center of Mr k421- in which the mass of the main black hole is 1.66 脳 108M.and the mass of the secondary black hole is 6.96 脳 104m. The authors analyzed the changes of Mrk421's color index, including the quasi-simultaneous V-R color index and the long-term B-V color index. It was found that Mr k 421 showed the phenomenon of "turning dark and red" when Mrk421 was in a low state. This phenomenon may be caused by the contribution of thermal radiation from host galaxies to a larger proportion when the target is dark.
【学位授予单位】：山东大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：P141

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