General Relativistic Simulations of Binary Compact Objects

使用移动穿刺方法，现在可以通过许多轨道、合并和最终黑洞的环灭来演化致密双星。主要任务变成了对不同物理问题进行精确建模。我们将使用这种方法来探索更实际的情况。特别是，我们计划解决几个关键的物理问题，如：(i)中子星自旋在中子星双星的演化中有多重要？（ii）我们如何才能最好地将一个很长的后牛顿螺旋形波形和一个从紧天体二进制中得到的数值波形结合起来？（iii）后牛顿波的频率可以被信任到什么程度，这个频率是如何依赖自旋和质量比的？（iv）如果我们使用更真实的初始数据，减少人工“垃圾”辐射，我们能否得到明显更好的波形？美国国家科学基金会的LIGO引力波探测器是世界上众多旨在直接探测和测量引力波的新设施之一。这些波将来自各种天体物理来源，并将打开一扇通往宇宙的新窗口。这些探测器最有希望的来源之一是紧天体双星（即包含黑洞或中子星的系统）的内螺旋和合并。当两个物体靠近时，需要对爱因斯坦方程进行完全非线性的数值模拟，以预测螺旋内的最后部分和随后的合并。我们的模拟产生的引力波将对其他科学团体（如LIGO合作）有价值。计划中的研究将涉及至少一名FAU的研究生和一名耶拿大学的博士后。因此，计划的研究将有教育效益的学生和博士后参与。他们不仅会学到与这个项目相关的科学知识，还会学到更广泛的超级计算机编程和数据管理知识。

Using the moving puncture approach, it is now possible to evolve compact-object binaries through many orbits, merger and the ringdown of the final black hole. The main task has become to accurately model different physical problems. We will use this method to explore more physically realistic situations. In particular, we plan to address several key physics issues such as: (i) How important is neutron star spin in the evolution of neutron star binaries? (ii) How can we best join a very long post-Newtonian in-spiral waveform and a numerically obtained waveform from a compact object binary? (iii) Up to which frequency can post-Newtonian waveforms be trusted, and how does this frequency depend on spins and mass ratios? (iv) Can we get significantly better waveforms if we use more realistic initial data with less artificial "junk" radiation? The NSF's LIGO gravitational wave detector is among a number of new facilities all over the world which are designed to directly detect and measure gravitational waves. These waves will come from a variety of astrophysical sources and will open a new window to the universe. One of the most promising sources for these detectors are the in-spirals and mergers of compact-object binaries (i.e., systems containing black holes or neutron stars). As the two objects get close, fully non-linear numerical simulations of the Einstein equations are required to make predictions about the final part of the in-spiral and subsequent merger. The gravitational waveforms produced by our simulations will be valuable for other scientific groups such as the LIGO collaboration. The planned research will involve at least one graduate student at FAU and one postdoc at the University of Jena. Thus the planned research will have educational benefits for the students and postdocs involved. They will not only learn about the science related to this project, but also more broadly about programming supercomputers and data management.