脉冲星的射电辐射谱及其VLBI天体测量研究

发布时间：2019-01-07 11:26

【摘要】：脉冲星自发现以来就一直是天文学家们关注的对象，在众多的研究方向中，脉冲星的辐射谱观测研究是热点之一，，也是人们了解脉冲星的内部物质构成、辐射机制及其所处的电磁环境等最直接的方式之一。同时代的VLBI的发展也为脉冲星的研究增色不少，更以极高的角分辨率带领着天体测量进入到了一个新的发展阶段。本文的研究内容分为两部分。在简述脉冲星的基本属性及研究方向的基础上，重点对脉冲星的辐射谱进行了研究，并对VLBI技术及其在我国的应用现状、未来发展需求也做了详细的阐述与讨论。本文首次利用大样本多波段观测数据，选取两种模型进行谱拟合，以自由自由吸收模型为主，采用线性最小二乘及非线性的LM两种方法进行曲线拟合，并对两种模型的结果图作了对比，分析了拟合参数误差的影响因素及模型的适用性。在结果中虽未发现毫秒脉冲星的辐射谱有倒转现象发生，但却发现其谱可能会在低频处发生倒转。 e-VLBI技术为当代VLBI的新发展，其利用高速通讯网络传送观测数据,能够快速得到观测结果，本文通过对e-VLBI发展历程的介绍，重点论述了VLBI技术在脉冲星观测与飞行器测定轨方面的应用现状，并讨论了我国未来新旧观测站设备配备的发展要求。
[Abstract]:Pulsars have been the focus of astronomers' attention since their discovery. Among the many research directions, the observation of pulsars' radiation spectrum is one of the hot spots, and it is also the understanding of the internal material composition of pulsars. Radiation mechanism and its electromagnetic environment is one of the most direct ways. At the same time, the development of VLBI has greatly enhanced the research of pulsars, and led the astrometry to a new stage of development with very high angular resolution. The research content of this paper is divided into two parts. Based on the brief description of the basic properties and research direction of pulsars, the radiation spectrum of pulsars is studied in detail, and the present situation of VLBI technology and its application in China, as well as the future development requirements, are also discussed in detail. In this paper, for the first time, two kinds of models are selected for spectral fitting using large sample multi-band observation data. The free absorption model is used as the main method, and the linear least square method and nonlinear LM method are used for curve fitting. The results of the two models are compared, and the factors affecting the error of fitting parameters and the applicability of the model are analyzed. Although no inversion of the spectrum of millisecond pulsars has been found in the results, it is found that the spectra of the pulsars may be reversed at low frequencies. E-VLBI technology is the new development of modern VLBI. It can get the observation result quickly by using high-speed communication network to transmit the observation data. This paper introduces the development course of e-VLBI. The application of VLBI technology in pulsar observation and spacecraft orbit determination is discussed in detail, and the development requirements of the equipment of new and old observation stations in China are also discussed.
【学位授予单位】：中国科学院研究生院(国家授时中心)
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：P145.6

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