MRI: Acquisition of a High-Capacity Data Analysis System for Gravitational-Wave Detection with Advanced LIGO

激光干涉仪引力波天文台（LIGO）是美国国家科学基金会资助的一个项目，用于探测引力波，即由超新星或中子星或黑洞对撞等剧烈天体物理事件发出的空间和时间涟漪。2015年9月对引力波的首次探测证实了科学中最基本理论之一的一个核心预测：爱因斯坦的广义相对论。有了这个和随后的探测，LIGO现在作为一个天文观测台运行，允许我们用一种全新的感觉来探索宇宙：引力波。该合同将为UWM提供计算资源，用于分析LIGO数据，并将加速LIGO仪器的发现。计算集群的设计是为了满足高级LIGO数据分析的特定需求。它是LIGO科学合作组织（LSC）努力的一个组成部分，用于分析完整的高级LIGO数据集。LIGO分析活动将优先考虑90%的集群；其余10%的其他活动将包括搜索射电脉冲星/瞬变星，利用nanogravity的脉冲星定时阵列探测引力波，以及数值天体物理学。在新聚类上运行的分析包括搜索压缩二进制和相关参数估计。该设施将向LSC的所有1000多个成员开放，因此将产生广泛的国际影响。此外，这些设施还被威斯康星大学和其他地方的研究人员用于天文学和天体物理学等领域的跨学科研究。这将继续下去，从而确保该仪器将在威斯康星大学和其他地方具有广泛的科学影响。该仪器的部署和使用还将为本科生、研究生、博士后科学家和学术人员提供一个动手教育和培训的机会，使他们能够使用大规模计算硬件来解决复杂的技术问题。基准计算仪器将由720个执行节点和2,280个现代E3-1241v3 CPU内核组成。该集团将增加几个高内存登录节点、存储服务器（总存储1152 TB）和网络设备。理论峰值性能将约为300 TFLOPS (AVX2)，具有足够的存储空间来容纳来自高级探测器的所有校准数据（30 TB/年）和几个月的原始数据（600 TB/年）。基准测试表明，集群将能够实时处理超过2800万个模板匹配。该项目的规模与LIGO数据分析任务的一个新方面相称，作为运行实时（秒延迟）搜索紧凑型双星合并的辅助站点，这项任务最好在专用站点（如UWM）处理。该仪器将促进和参与发现和研究宇宙中产生引力波的奇异天体物理事件。该合同将提供分析数据所需的部分计算资源，因为这些数据是由新的先进LIGO仪器提供的。它将支持一系列科学活动，包括探测新的引力波信号以及更广泛的天体物理学和天文学后续分析。

The Laser Interferometer Gravitational Wave Observatory (LIGO) is an NSF-funded project to detect gravitational waves, the ripples in space and time emitted by violent astrophysical events such as supernovae or colliding pairs of neutron stars or black holes. The first detection of these waves in September 2015 confirmed a central prediction of one the most fundamental theories in science: Einstein's theory of general relativity. With this and subsequent detections, LIGO is now operating as an astronomical observatory allowing us to explore the Universe using a completely new sense: gravitational waves. This award provides computing resources at UWM to analyze the LIGO data and will accelerate the discoveries enabled by the LIGO instruments. The computing cluster is designed to address the specific needs of Advanced LIGO data analysis. It is an integral part of the LIGO Scientific Collaboration (LSC) effort to analyze the full Advanced LIGO data sets. LIGO analysis activities will be prioritized on 90% of the cluster; other activities on the remaining 10% will include searches for radio pulsars/transients, the detection of gravitational waves using pulsar timing arrays by NANOGrav, and numerical astrophysics. Analyses to be run on the new cluster include searches for compact binaries and related parameter-estimation. The facility will be available to all 1000+ members of the LSC, and thus will have broad international impact. Moreover, these facilities have also been used by researchers at UWM and elsewhere for interdisciplinary research in fields such as astronomy and astrophysics. This will continue, thus ensuring that this instrument will have a broad scientific reach at UWM and beyond. The deployment and use of this instrument will also provide a hands-on opportunity for education and training to undergraduates, graduate students, post-doctoral scientists and academic staff in the use of large-scale computing hardware to tackle complex technical questions.The baseline computational instrument will consist of 720 execute nodes with 2,280 modern E3-1241v3 CPU cores. The group will add several high-memory login nodes, storage servers (1,152 TB gross storage) and networking equipment. Theoretical peak performance will be about 300 TFLOPS (AVX2) with sufficient storage to host all of the calibrated data from advanced detectors (30 TB/yr) and several months of raw data (600 TB/yr). Benchmarks indicate that the cluster will be able to process over 28 million template matches in real time. The scale of this project is commensurate with a new aspect of this mission within LIGO data analysis as a secondary site for running the real-time (latency of seconds) search for compact binary mergers -- a task best handled at a dedicated site such as UWM. This instrument will facilitate and participate the discovery and the study of the exotic astrophysical events throughout the Universe that produce gravitational waves. This award will provide part of the computational resources needed to analyze the data as it is delivered by the new Advanced LIGO instruments. It will support an array of scientific activities including the detection of new gravitational-wave signals and the broader astrophysical and astronomical follow-on analyses.