致密双星的进动效应研究

发布时间：2018-05-21 09:23

本文选题：脉冲星 + 自转-轨道耦合　；参考：《华中科技大学》2011年硕士论文

【摘要】：脉冲星是快速旋转的中子星，它是60年代天文学的四大发现之一。1974年，美国的赫尔斯和泰勒发现了第一颗射电脉冲双星PSR1913＋16，它们是两颗互相环绕的脉冲星，轨道周期很短，仅为7.75小时。轨道的偏心率为0.617。当两颗子星相互靠得很近时，极强的引力辐射会导致它们的距离愈加靠近，，轨道周期会逐渐变短。但是脉冲双星中存在很多源用现有理论无法解释观测到的脉冲星到达时间及其轮廓，并且有某些确切观测表明某些脉冲双星中轨道周期的一阶导数小于0，且会改变符号；即双星中的轨道周期随着时间演化越来越长，双星的距离越来越远。而引力波辐射将引起的周期的变短。对于这些脉冲星公认的疑难问题，若能够解决那么必然意义深远重大。在广义相对论中，由于自转必然会产生能量动量张量，因此会对双星系统的运动产生影响。因此对于进动效应Damour等人考虑由自转-轨道耦合(Spin-OrbitCoupling)引起的附加项[1]，成功解释了一些观测现象。但是仅仅考虑自转-轨道耦合的效应还是有些问题解决不了：1998年Wex~([2-4])对于PSR B1259-63提出了到达时间模型，在7年两个轨道周期的时间内精确的拟合了此双星系统的到达时间。2004年王娜等给出了13年的PSR B1259-63到达时间~([5-6])，发现采用Wex的时间模型到达时间在后两个周期观测曲线与理论曲线完全不相符，这个问题至今未解决。本工作考虑自转-自转耦合(Spin-Spin Coupling)效应，首先由体系总哈密顿量根据哈密顿正则方程得到体系的矢量、标量运动方程，与仅考虑自转-轨道耦合情况时相比较；其次，类比于damour所采用的后牛顿近似方法，得到三阶后牛顿近似下（无自转）轨道运功方程精确解的求解；接着我们加入自转-轨道耦合项，得到自转-轨道耦合与三阶后牛顿效应下轨道方程精确解推导；最后我们根据天体物理中双星系统的一些近似处理得到了在考虑自转-自转耦合效应之下双星系统的进动效应。
[Abstract]:Pulsars are fast rotating neutron stars, one of the four great discoveries of astronomy in the 1960s. In 1974, Hulse and Taylor in the United States discovered the first radio pulsars, PSR 193 + 16, two pulsars orbiting each other for a short period of time. Only 7.75 hours. The eccentricity of the orbit is 0. 617. When the two sub-stars are very close to each other, the strong gravitational radiation will cause them to get closer and the orbital period will gradually become shorter. However, there are many sources in the binary pulsar which can not explain the observed time of arrival and its contour by existing theories, and some exact observations show that the first order derivative of the orbital period in some pulsating binary stars is less than 0, and the symbol will be changed. In other words, the orbital period in binary stars is getting longer and longer with time, and the distance between binary stars is getting farther and farther. And the gravitational wave radiation will cause the period to become shorter. For these pulsar recognized problems, if it can be solved, it is of great significance. In general relativity, the motion of binary star system will be influenced by rotation, which is bound to produce Zhang Liang of energy and momentum. Therefore, for the precession effect, Damour et al consider the additional term [1], which is caused by the spin-OrbitCoupling of the rotation-orbit coupling, and successfully explain some observational phenomena. However, there are still some problems that can not be solved by considering the rotation-orbit coupling effect: in 1998, Wexi ([2-4]) proposed a time of arrival model for PSR B1259-63. The arrival time of the binary system was accurately fitted in the time of two orbital periods of 7 years. In 2004, Wang Na et al gave the arrival time of PSR B1259-63 for 13 years ([5-6]). It was found that the arrival time of the time model using Wex was observed in the latter two periods. The line is completely out of line with the theoretical curve. The problem remains unresolved. In this paper, the spin coupling effect is considered. Firstly, the vector and scalar motion equation of the system are obtained from the total Hamiltonian equation of the system, which is compared with that when only the rotation orbit coupling is considered. Secondly, the total Hamiltonian quantity of the system is obtained according to the Hamiltonian canonical equation, and the equations of motion of the system are compared with those under the condition of only considering the rotation and orbit coupling. By analogy with the post-Newton approximation method used by damour, the exact solution of the (no rotation) orbital work equation under the third order post-Newton approximation is obtained, and then we add the rotation-orbit coupling term. The exact solution of the orbit equation under the rotation orbit coupling and the third order Newton effect is derived. Finally, according to some approximate treatments of the binary star system in astrophysics, the precession effect of the double star system considering the rotation coupling effect is obtained.
【学位授予单位】：华中科技大学
【学位级别】：硕士
【学位授予年份】：2011
【分类号】：P144.9

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