黑洞—脉冲星系统强引力中的光传播效应

发布时间：2018-07-06 12:01

本文选题：银心 + 脉冲星-黑洞双星　；参考：《中国科学技术大学》2014年硕士论文

【摘要】：脉冲星是宇宙中最精确的时钟,其信号周期的精确度能够超过原子钟。1979年,Hulse和Taylor发现了脉冲双星PSR B1913+16(脉冲星带有一个中子星伴星),该系统轨道周期的衰减率与广义相对论预言的由引力辐射造成的轨道衰减相符合,这间接验证了引力波的存在。到目前为止,广义相对论仅仅在弱场(例如太阳系)中被正确检验,脉冲双星的发现为未来在强场中精确检验广义相对论提供了可能。若脉冲星的伴星是一个黑洞,那么引力效应将更加显著,我们可以利用脉冲星精准的脉冲到达时间作为研究强引力物理和黑洞性质的探针。本文研究的对象是脉冲星围绕星系中心超大质量黑洞做轨道运动的双星系统。脉冲星发出的脉冲在到达地球的过程中,如果途径黑洞附近,会被强引力场弯曲,原则上可以通过观测接收到的脉冲来研究黑洞和强引力场的性质。我们以围绕银河系中心超大质量黑洞Sgr A*做圆周运动的脉冲星为例,分析了强引力场对脉冲路径的影响和脉冲到达时间的延迟。结果表明,脉冲轨迹和时延敏感依赖于观测者的观测倾角。观测角越大,强引力场效应就越显著。相比于黑洞的引力质量,黑洞自旋对结果的影响较小；当观测者偏离脉冲星轨道平面较大(即观测角较小时),黑洞自旋造成的效应明显变小；因此,需要借助高精度和灵敏度的望远镜来探究黑洞自旋的影响。随着大型射电望远镜FAST、SKA等的建成使用,我们有理由相信,发现更多、距离Sgr A*更近的脉冲星指日可待。
[Abstract]:Pulsars are the most accurate clocks in the universe, In 1979, Hulse and Taylor discovered the pulsars PSR B191316 (pulsar with a neutron star companion), the decay rate of the orbital period of the system and the gravitational radiation predicted by the general relativity. The resulting orbital decay is consistent, This indirectly verifies the existence of gravitational waves. So far, general relativity has only been correctly tested in weak fields (such as the solar system), and the discovery of pulsating binary stars has made it possible to accurately test general relativity in strong fields in the future. If the pulsar's companion is a black hole, the gravitational effect will be more significant. We can use the pulsar's precise pulse arrival time as a probe to study the properties of strong gravitational physics and black hole. The object of this paper is a binary system of pulsars orbiting supermassive black holes in the center of galaxies. In the process of reaching the earth the pulsars will be bent by the strong gravitational field if the path is near the black hole. In principle the properties of the black hole and the strong gravitational field can be studied by observing the received pulse. In this paper, the influence of strong gravitational field on the pulse path and the delay of the arrival time of the pulse are analyzed by taking the pulsar with circular motion around the supermassive black hole Sgr A * in the center of the Milky way as an example. The results show that the pulse trajectory and time delay sensitivity depend on the observational inclination. The larger the observation angle, the more significant the strong gravitational field effect is. Compared with the gravitational mass of the black hole, the spin of the black hole has less effect on the result. When the observer deviates from the plane of the pulsar orbit (that is, the observation angle is small), the effect caused by the spin of the black hole is obviously smaller. High precision and sensitivity telescopes are needed to explore the effects of black hole spin. With the completion and use of the large radio telescope FASTX SKA, we have reason to believe that more pulsars closer to Sgr A * are within reach.
【学位授予单位】：中国科学技术大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：P145.6;P145.8

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