Investigations in Gravitational Radiation - Support of LIGO Observing Run 3

本申请涉及STFC ST/N005430/1。爱因斯坦的广义相对论预言，处于强引力场中的动力系统会以引力波的形式释放出大量的能量。这些波是时空结构中的涟漪，以光速从源头传播出去，并携带着产生它们的物理过程的信息。虽然强大，但由引力波造成的时空扭曲非常小，这使得它们很难被探测到。几十年来，STFC一直是LIGO项目的合作伙伴，该项目使用尖端技术操作千米级探测器。2015年9月14日，当LIGO探测到遥远星系中一对黑洞猛烈合并产生的引力波时，爱因斯坦的理论得到了惊人的证实。从那以后，又有9个黑洞合并的引力波被证实。此外，2017年8月17日，LIGO及其合作天文台室女座探测到一对中子星合并产生的引力波，这对中子星是由死去的恒星烧毁的核心。将引力信号与碰撞中发出的光进行比较，导致了天体物理学和宇宙学的几项重大突破。其中包括对宇宙膨胀率的直接测量（“哈勃常数”），以及宇宙中大多数重元素（如金和铂）都是在这些中子星合并中产生的有力证据。世界范围内的探测器网络包括美国先进的激光干涉仪引力波天文台（LIGO），法国-意大利-荷兰-波兰先进的Virgo，德国-英国GEO600，以及日本正在建设的KAGRA探测器。LIGO和Virgo将于2019年中早期开始第三次观测，收集数据，寻找更多的黑洞、中子星和其他奇异现象。这项拨款支持的研究将有助于扩大新数据的科学效益。专门的研究人员将开发技术，以确定黑洞和中子星在最终碰撞前后甚至之前的位置，使天文学家能够研究合并后关键的最初几分钟发出的光。他们还将研究我们如何从引力波信号中推断出迄今未知的中子星内部结构，从而探索在宇宙中发现的一些最极端条件下物质的特性。

This application relates to STFC ST/N005430/1.Einstein's General Theory of Relativity predicts that dynamical systems in strong gravity fields will emit vast amounts of energy in the form of gravitational waves. These waves are ripples in the very fabric of spacetime, that spread out from their sources at the speed of light, and carry information about physical processes that created them. While powerful, the distortion of spacetime created by the waves is incredibly small, making them challenging to detect. For several decades STFC has been a partner in the LIGO project, which operates kilometer-scale detectors with cutting edge technology. On 14 Sept 2015, Einstein's theory was confirmed spectacularly when LIGO detected gravitational waves from the violent merger of a pair of black holes in a distant galaxy. Since then gravitational waves from a further nine black-hole mergers have been confirmed. In addition, on 17 August 2017 LIGO and its partner observatory Virgo detected gravitational waves from the merger of a pair of neutron stars -- burned out cores of dead stars. Comparison of gravitational signal to light emitted in the collision lead to several spectacular breakthroughs in astrophysics and cosmology. These included a direct measurement of the expansion rate of the Universe (the "Hubble constant"), and strong evidence that most of the heavy elements in the Universe such as gold and platinum are produced in these neutron star mergers.The worldwide network of detectors includes the American advanced Laser Interferometer Gravitational-Wave Observatory (LIGO), the French-Italian-Dutch-Polish advanced Virgo, and the German-UK GEO600, plus the KAGRA detector under construction in Japan. LIGO and Virgo will start the third observing run in early-mid 2019, pooling their data in the hunt for further black holes, neutron stars, and other exotic phenomena. The research supported by this grant will help to extend the scientific benefit from the new data. Dedicated researchers will develop techniques for determining the location of merging black holes and neutron stars in the moments around or even before the final collision, enabling astronomers to study the light given off in the critical first minutes following the merger. They will also investigate how we can infer the as-yet-unknown interior structure of neutron stars from the gravitational-wave signal, thereby probing the properties of matter under some of the most extreme conditions found in the Universe.