Precision Measurements of the Black-Hole Properties in the Center of the Milky Way

银河系中心的黑洞Sgr A* 是我们银河系中所有已知黑洞中质量最大的。也是宇宙中所有超大质量黑洞中最接近的。这种大质量和小距离的组合使Sgr A* 成为强场区域中高能和引力天体物理学的最终测试平台。在不久的将来，仪器方面的重大发展将提供工具，通过观测恒星轨道中的相对论效应、双星的计时以及其吸积流的地平线尺度图像，对其时空进行高精度研究。PI和他的合作者将调查天体物理学的复杂性，这可能会限制对黑色天体的精确测量，孔属性与每一种技术，并制定方法来克服它们。这项工作将使他们能够利用NSF在技术方面的投资，例如Event Horizon Telescope和GBT，以及在亚利桑那大学建造基于GPU的计算机集群，该集群通过NSF-MRI奖成为可能。在拟议的项目期间，一名研究生将接受预测强者的教育，天体物理学黑洞的场特性，并在分析未来数据的统计工具的实施。PI和CoPI还致力于通过在拟议项目期间组织跨学科科学会议，在科学界更广泛地传播研究活动。他们还通过非技术性的公开讲座和演示向公众传播科学成果。

The black hole in the center of the Milky Way, Sgr A*, is the most massive among all the known black holes in our galaxy. Is also by far the closest among all the supermassive black holes in the universe. This combination of a large mass and a small distance makes Sgr A* the ultimate test-bed of high-energy and gravitational astrophysics in the strong field regime. In the near future, major developments in instrumentation will provide the tools for high-precision studies of its space-time via observations of relativistic effects in stellar orbits, in the timing of pulsars, and in horizon-scale images of its accretion flow.In the proposed research project, the PI and his collaborators will investigate the astrophysical complexities that may limit precise measurements of the black-hole properties with each technique and devise ways to overcome them. This work will allow them to capitalize on the NSF investment in technologies, such as the Event Horizon Telescope and the GBT, as well as on the construction of a GPU-based computer cluster at the University of Arizona that became possible through an NSF-MRI award.During the proposed project, one graduate student will be educated in predicting the strong-field properties of astrophysical black holes and in implementing statistical tools for analyzing future data. The PI and CoPI are also committed to the broader dissemination of the research activities in the scientific community by organizing interdisciplinary scientific conferences during the time of the proposed project. They are also engaged in communicating the scientific results to the general public via non-technical public lectures and demonstrations.