黑洞对电磁辐射传播所产生的观测效应

发布时间：2018-01-13 03:01

本文关键词：黑洞对电磁辐射传播所产生的观测效应　出处：《南京大学》2011年博士论文　论文类型：学位论文

【摘要】：爱因斯坦于1915年完成了广义相对论,它统一了狭义相对论和牛顿的万有引力理论。作为引力的几何理论,广义相对论把引力描述为时空的弯曲。大约从二十世纪六十年代初开始,广义相对论已经在太阳系的弱引力场环境下被许多的实验所检验。而强引力场总是伴随着致密的星体,比如说黑洞或者中子星。1979年,Hulse和Taylor发现脉冲双星PSR B1913+16(由一对中子星组成,其中之一是脉冲星)轨道周期的衰减率与广义相对论预言的由引力波释放能量导致的轨道衰减率吻合。这个发现为引力波的存在提供了一个间接的证据。尽管广义相对论已经被一系列的实验所证实,但是它还没有在强场的条件下被高精度的检验过。其中的主要困难之一是强场的效应总是被来自天体物理系统中复杂和不确定的非引力场效应所污染。相比较而言,在太阳系的检验中,弱场的效应在大多数的情况下可以与非引力场的效应分离。尽管如此,随着理论和实验方法的进步,越来越多的强场效应的观测方面开始被研究。本论文的目的是研究黑洞引力场所产生的观测效应,主要包括两个不同的天体物理系统。第一个系统包含一个超大质量黑洞和一个脉冲星,当脉冲星的脉冲信号经过超大质量黑洞附近时,强引力场将会对其到达时间和强度产生影响(第2和第3章)。第二个系统包含一个恒星质量或者超大质量的黑洞以及一个环绕其运动的扭曲的吸积盘。黑洞的强引力场和自旋将会对吸积盘上产生的发射线的轮廓产生影响(第4章)。为了条理清晰起见,本论文划分为5章。第一章是对本论文的研究中涉及到的理论背景知识作一个简要的介绍,主要包括广义相对论、中子星、黑洞及其吸积盘和弯曲时空中粒子和光子的运动。在第二章中,我们考虑了一个脉冲星围绕超大质量黑洞旋转的系统,进而我们研究了当脉冲星的脉冲信号经过超大质量黑洞附近时强引力场对其强度和计时所产生影响。对于黑洞的自旋可以被忽略的情况,我们证明了所有的强场对脉冲束的影响可以通过两个“通用函数”来理解。其中一个函数是用来计算光子轨迹的偏折,另一个是用来计算光子在这条轨迹上运动所需的时间。我们称这两个函数是通用的是因为它们只依赖于一个参数,也就是脉冲信号发射时脉冲星与黑洞的距离。作为例子,我们把这个方法应用到一个在圆轨道上运动并且把其脉冲辐射发射在轨道平面内的脉冲星。除了通过大致直接的轨道到达观测者的主脉冲外,我们发现了二级和更高级的脉冲。一般而言,它们会比主脉冲微弱很多,但是当它们在脉冲星处于黑洞最远端处被发射时,它们的强度就有可能可比于甚至超过主脉冲。我们的结果显示主脉冲和二级脉冲之间存在相位的关系,这可以用来作为强弯曲时空几何的探针。类似的现象也会出现在更一般的构型中,比如一个围绕黑洞旋转的脉冲星把脉冲辐射发射到轨道平面外的任意方向。在第三章中,我们把“通用函数”方法应用到了更加一般的脉冲星-黑洞-观测者的几何位型中,其中脉冲星自旋轴的方向,脉冲束的辐射方向和张角宽度都是任意的。我们证明对于这类系统,观测问题的分析可以分解为两个不同的部分：(i)依赖于观测者的“锁孔”(也就是观测者可以接受到信号的脉冲发射方向)的位置和轨迹的计算；(ii)对代表包含发射束能量方向的环带的判定。每个部分的例子与对应的一个具体的观测实例都在本章中一并给出。在第四章中,我们考虑一个扭曲的吸积盘环绕着Kerr黑洞旋转的系统。如果这个吸积盘被来自盘冕中的非热的硬X射线所照射,那么由于荧光机制,铁的发射线将会从吸积盘的内区产生。发射线的轮廓表现出各种各样的由于强引力场所产生的观测特征,因此它可以用来探测Kerr黑洞的自旋参数以及扭曲的吸积盘的结构。这里我们推广了之前的相对论铁线轮廓的模型,同时包含了黑洞的自旋效应以及扭曲的吸积盘的非轴对称性。我们的计算显示了一些与传统上对于平坦的吸积盘围绕Kerr黑洞和扭曲的吸积盘围绕Schwarzschild黑洞的计算不同的特征。这主要包括了谱线的多峰结构,红端很长的线翼,以及谱线轮廓随着盘进动所产生的时变等等。同时我们也展示了遥远观测者可能会看到的由于强场所导致的畸变的吸积盘的图像。这里的计算是具有一般性的,可以应用于任何来自扭曲的吸积盘的发射线。在第五章中,我们总结了在这篇论文中涉及到的黑洞对电磁辐射传播所产生的观测效应,并且对我们今后可能进行的强场效应方面的研究作了展望。
[Abstract]:In 1915 Einstein completed the general theory of relativity, it unifies special relativity and Newton's theory of gravitation. As the geometric theory of gravity, general relativity describes gravity as space-time bending. About from the beginning of 1960s, general relativity has weak gravitational field environment in the solar system is tested by many experiments while strong gravitational field is always accompanied by compact objects such as black holes or neutron stars in.1979, Hulse and Taylor found that PSR B1913+16 (binary pulsar, a neutron star of one of them is Mai Chongxing) the decay rate of track cycle and general relativity prediction of gravitational wave energy caused by orbital decay rate well. This discovery provides an indirect evidence for the existence of gravitational waves. Although general relativity has been confirmed by a series of experiments, but it is not in the strong field Test conditions are of high precision. One of the main problems which is the strong field effects are from astrophysical systems in complex and uncertain non gravitational effects of pollution. In comparison, in the inspection of the solar system, weak field effects in most cases with the separation of non gravitational effect field. However, with the advances of theoretical and experimental methods, observational aspects of strong field effects in increasing numbers are beginning to be studied. The purpose of this paper is the observation effect on black hole gravitational field, including two different celestial physics system. The first system contains a supermassive black hole and a the pulsar, when the pulsar pulse signal passed close to the supermassive black hole, the strong gravitational field will be the arrival time and the impact strength (second and third). The second system contains a stellar mass or Zhe Chao A massive black hole and a twisted accretion disk that surround its motion. The strong gravitational field and spin of black holes will have an impact on the contour of the emission line generated on the accretion disk (the fourth chapter).
For the sake of clarity, this paper is divided into 5 chapters. The first chapter is a brief introduction to the theoretical background knowledge involved in this study, including general relativity, neutron stars, black holes and their accretion disks, and the motion of particles and photons in curved spacetime.
In the second chapter, we consider a pulsar around the supermassive black hole rotation system, and then we study when the pulsar pulse signal passed close to the supermassive black hole strong gravitational field influence on the intensity and timing. For the spin of the black hole can be neglected, we prove that all the strong field effects on the pulsar beam can be understood by the two "general function". One function is used to calculate the deflection of photon trajectories, the other one is used to calculate the motion of photons in this track on the time required. We call these two functions are general because they only depend on a parameter, which is the distance from the pulse signal is emitted pulsars and black holes. As an example, we apply this method to a motion in circular orbit and its pulses into the orbital plane of the pulsar. In addition to the main pulse by roughly direct track to the observer, we found two grade and higher pulse. In general, they are much dimmer than the primary pulses, but when they are in the black hole at the far end is launched in the pulsar, their strength might be comparable to or even more than the main pulse. The main pulse and two pulse phase between the relationship of our results show that it can be used as a strong curved spacetime geometry of the probe.
A similar phenomenon will appear in more general configurations, such as a black hole around the pulsar rotation of the arbitrary pulse radiation is emitted into the orbit plane. In the third chapter, we put the "universal function" method to the observer general pulsar black hole - geometry. The star spin axis direction and the pulse, pulse beam radiation direction and angular width is arbitrary. We prove that for this kind of system, the observation and analysis of the problem can be decomposed into two different parts: (I) an observer dependent "keyhole" (that is, the observer can receive pulse transmitting direction signal calculate the position and track); (II) judgment on behalf of ring containing beam energy direction. A concrete example of each part of the observed examples and the corresponding are given in this chapter.
In the fourth chapter, we consider a warped Accretion Disc around a rotating black hole Kerr system. If the hard X ray non thermal accretion disk from the disk corona by irradiation, so the fluorescence mechanism, iron lines will be emitted from the inner region of the accretion disc. The emission line profile performance produced due to the strong gravitational field observations of a variety of characteristics, so it can be used to detect the Kerr black hole spin parameters and the structure of the accretion disk. Here we generalize the previous relativistic line profile model, including the black hole spin effect of the accretion disk and the asymmetry of the US. The calculation shows that some traditional for a flat disk Accretion Disc around a Kerr black hole and twisted around the Schwarzschild black hole calculation of different characteristics. It mainly includes the multi peak structure of spectral line, the red end is very long The wing of the line, and the line profiles with disk precession generated by the variable and so on. At the same time we also show a distant observer may see the result due to the strong place of distortion of the accretion disc image. The calculation is general and can be applied to any from the accretion disk emission lines.
In the fifth chapter, we summarize the observational effects of black holes on electromagnetic radiation propagation in this paper, and make a prospect for our future research on strong field effect.

【学位授予单位】：南京大学
【学位级别】：博士
【学位授予年份】：2011
【分类号】：P162

【共引文献】