论文标题
相对论的传播和框架拖动时间延迟在旋转超质量黑洞Sgra*的时机的时间延迟*
Relativistic propagation and frame dragging time delay in the timing of a pulsar orbiting the supermassive black hole SgrA*
论文作者
论文摘要
在银河系中心的超质量黑洞Sgra*周围的近距离轨道中计时脉冲星，将打开窗口，以准确确定黑洞参数，并为一般相对论和替代性修饰的重力理论进行新的测试。必须在定时模型中考虑的重要相对论效应是黑洞重力场中脉冲的传播延迟。由于脉冲星和超质量后孔的极高质量比，我们使用测试粒子极限来得出一个精确的分析公式，用于KERR时空的传播延迟，并推断出相对论公式对框架拖动对到达时间的效果。作为例证，我们处理一个边缘轨道，其中框架拖动效果的最大值。我们将我们的传播时间延迟的公式与牛顿后的方法进行了比较，尤其是Wex＆Kopeikin和Rafikov＆Lai在先前作品中得出的框架拖动术语。我们的方法正确地识别了框架拖动延迟相对于上级连接的不对称性，避免了时间延迟的奇异性，并指出在牛顿后的进近进近框架拖动效果通常会稍微高估。
Timing a pulsar in a close orbit around the supermassive black hole SgrA* at the center of the Milky Way would open the window for an accurate determination of the black hole parameters and for new tests of General Relativity and alternative modified gravity theories. An important relativistic effect which has to be taken into account in the timing model is the propagation delay of the pulses in the gravitational field of the black hole. Due to the extreme mass ratio of the pulsar and the supermassive back hole we use the test particle limit to derive an exact analytical formula for the propagation delay in a Kerr spacetime and deduce a relativistic formula for the frame dragging effect on the arrival time. As an illustration, we treat an edge-on orbit in which the frame dragging effect is expected to be maximal. We compare our formula for the propagation time delay with Post-Newtonian approaches, and in particular with the frame dragging terms derived in previous works by Wex & Kopeikin and Rafikov & Lai. Our approach correctly identifies the asymmetry of the frame dragging delay with respect to superior conjunction, avoids singularities in the time delay, and indicates that in the Post-Newtonian approach frame dragging effects are generally slightly overestimated.
