Numerical Simulations of Compact Neutron Star Binary Mergers

该奖项资助对中子双星和由中子星星和黑洞组成的双星合并的研究。 这些现象是地面探测器（如激光干涉引力波天文台（LIGO））的主要引力辐射源之一，它们可以解释观测到的短持续时间伽马射线暴（GRB）。 需要计算机模型来计算这些合并的预期引力波形，并测试它们作为伽马射线暴源的可行性。 该项目将对黑洞-中子星星和中子星-中子星星合并进行大规模、详细的计算机模拟，重点关注三个主要问题。 首先，它将研究合并后黑洞周围留下的核物质碎片的演变，特别是磁场和中微子辐射的影响，这些影响预计在向GRB提供能量方面至关重要。 其次，它将通过模拟目前尚未研究的黑洞质量和自旋的极端情况来探索黑洞-中子星星双星的多样性。 第三，研究中子星星物理对引力波形的影响，准确的引力波形预测对于探测LIGO数据中的双星合并信号和提取中子星星结构信息至关重要。 这些信息可能能够限制核物质的未知性质。 为这个项目开发的数值技术将适用于天体物理流体动力学的其他问题。 该奖项的大部分资金用于学生支持。 PI指导研究生和本科生。 这些学生接受计算机编程，数值问题解决和流体力学方面的宝贵培训，获得适用于广泛技术领域的重要技能。 该项目的成果将用于向更广泛的公众传达天体物理学的兴奋。

This award funds research into mergers of binary neutron stars and of binaries consisting of a neutron star and a black hole. These phenomena are among the primary sources of gravitational radiation for ground-based detectors such as the Laser Interferometer Gravitational Wave Observatory (LIGO), and they may explain the observed short-duration gamma ray bursts (GRBs). Computer models are needed both to calculate the expected gravitational waveforms for these mergers and also to test their viability as sources of GRBs. This project will carry out large-scale, detailed computer simulations of black hole-neutron star and neutron star-neutron star mergers, focusing on three main issues. First, it will study the evolution of the nuclear matter debris left around the post-merger black hole, especially the effects of magnetic fields and neutrino radiation that are expected to be critical in delivering energy to a GRB. Second, it will explore the variety of black hole-neutron star binaries by modeling currently unstudied extremes of black hole mass and spin. Third, it will characterize the effects of neutron star physics on the gravitational waveforms.Accurate gravitational waveform predictions will be crucial for detecting binary merger signals in LIGO data and for extracting information about the neutron star structure. Such information might be able to constrain unknown properties of nuclear matter. Numerical techniques developed for this project will be applicable to other problems in astrophysical fluid dynamics. Most of the funding from this award is used for student support. The PI directs both graduate and undergraduate students. These students receive valuable training in computer programming, numerical problem solving, and hydrodynamics, gaining important skills applicable to a broad range of technical fields. Results from this project will be used in communicating the excitement of astrophysics to the wider public.