AccelNet-Implementation: The International Pulsar Timing Array

引力波是时空中的涟漪，爱因斯坦的广义相对论预言了它的存在。它们由加速的大质量物体发射，以光速传播，不受星系、恒星和气体等物质的阻碍。2015年，LIGO的合作探测到了来自两个黑洞合并的引力波，使天文学家能够“看到”以前看不见的物体，并探测宇宙中最高能量的过程。国际脉冲星定时阵列(IPTA)是一个由研究人员和学生组成的全球网络，致力于通过使用世界上最大的射电望远镜观测被称为射电脉冲星的精确天钟，直接探测比LIGO小11个数量级的频率的引力。这一AccelNet实施项目将扩大IPTA的覆盖范围，使其超越来自北美、欧洲和澳大利亚的研究人员和学生，包括中国、印度和南非。除了加强对分布在天空中的脉冲星的观测外，扩大后的IPTA网络还将为学生和博士后研究人员提供复杂的网络基础设施和培训，涉及天体物理、射电仪器、信号处理和数据科学。IPTA希望在合并星系的核心探测到来自超大质量双星黑洞的引力波。这些探测将为银河系的生长和演化提供新的见解，改变我们对宇宙的理解。到获奖期结束时，IPTA将探测和表征宇宙中所有超大质量双星黑洞产生的引力波的随机背景。它还可能探测到第一个突出于背景之上的单个超大质量黑洞双星。这种研究的国际协调还将产生非常高影响的协同科学，如中子星质量测量、星际介质的表征、广义相对论测试，以及发现奇异的脉冲星系统和射电瞬变，如快速射电爆发。将通过年度讲习班、会议以及共享数据和分析门户网站促进协调。IPTA的学生和博士后研究人员将参与一个国际指导网络，并将学习宝贵的推广技能，同时将这项工作的兴奋带给世界各地的K-12学生。通过国际网络到网络合作加速研究(AccelNet)计划旨在加快科学发现的进程，并为多团队国际合作培养下一代美国研究人员。AccelNet计划支持美国研究网络和海外互补网络之间的战略联系，这些网络将利用研究和教育资源来应对需要重大国际协调努力的重大科学挑战。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Gravitational waves are ripples in spacetime, predicted to exist by Einstein's theory of general relativity. They are emitted by accelerating, massive objects and travel at the speed of light, unimpeded by matter such as galaxies, stars, and gas. Gravitational waves from the merger of two black holes were detected by the LIGO collaboration in 2015, allowing astronomers to "see" previously invisible objects and probe the most energetic processes in the universe. The International Pulsar Timing Array (IPTA) is a world-wide network of researchers and students working to directly detect gravitational at frequencies 11 orders of magnitude smaller than LIGO through observations of precise celestial clocks called radio pulsars using the world's largest radio telescopes. This AccelNet-Implementation project will broaden the reach of the IPTA beyond researchers and students from North America, Europe, and Australia to include China, India, and South Africa. In addition to enhancing observations of pulsars distributed across the sky, the expanded IPTA network will provide sophisticated cyber-infrastructure and training for students and postdoctoral researchers in astrophysics, radio instrumentation, signal processing, and data science. The IPTA expects to detect gravitational waves from supermassive binary black holes at the cores of merging galaxies. These detections will provide new insights into galaxy growth and evolution through cosmic time, transforming our understanding of the Universe. By the end of the award period, the IPTA will detect and characterize the stochastic background of gravitational waves produced by all the supermassive binary black holes in the Universe. It is also likely to detect the first individual supermassive black hole binary that stands out above the background. This international coordination of research will also result in very high impact synergistic science such as neutron star mass measurements, characterization of the interstellar medium, tests of general relativity, and the discovery of exotic pulsar systems and radio transients such as Fast Radio Bursts. Coordination will be facilitated through annual workshops, meetings, and shared data and analysis portal. Students and postdoctoral researchers in the IPTA will be involved in an international mentoring network and will learn valuable outreach skills, while at the same time bringing the excitement of this work to K-12 students worldwide.The Accelerating Research through International Network-to-Network Collaborations (AccelNet) program is designed to accelerate the process of scientific discovery and prepare the next generation of U.S. researchers for multiteam international collaborations. The AccelNet program supports strategic linkages among U.S. research networks and complementary networks abroad that will leverage research and educational resources to tackle grand scientific challenges that require significant coordinated international efforts.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.