Testing Accretion Physics and Strong-Field Gravity by Imaging Accreting Black Holes

AST-0907890 Loeb天空中最大的两个黑洞分别位于Sgr A*（银河系中心）和M87星系中心。 最近的观测表明，它们的视界的表观大小，天空中的几十微弧秒，可以通过亚毫米波长的甚长基线干涉测量（VLBI）来解决。 利用现有技术对这些黑洞的轮廓进行成像，为探索广义相对论、吸积流物理学和相对论流出的发射场打开了一扇新的窗口。 这个项目将详细研究这些轮廓对周围气体的背景照明。 的主要目标是检查的灵敏度的功能在图像中的吸积流和射流物理的细节，并分离功能，提供通用的广义相对论的测试。 模拟将使用广义相对论代码，其中包括射线跟踪，气体动力学和相关的等离子体物理。 第二阶段将研究未来的观测如何解决预测的图像，以优化观测策略，并在给定的观测时间内获得最科学的输出。在强场极限下测试广义相对论对基础物理学非常重要，而黑洞一直以来都吸引着公众的兴趣。 该作品的黑洞轮廓图像将通过博物馆和流行媒体通过流行级别的文章和电影免费向每个人提供。

AST-0907890LoebThe two largest black holes on the sky are in Sgr A* (at the center of our Galaxy) and in the center of galaxy M87. Recent observations have demonstrated that the apparent size of their horizons, tens of micro-arcseconds on the sky, can be resolved by Very Long Baseline Interferometry (VLBI) at sub-millimeter wavelengths. Imaging the silhouette of these black holes with existing technology opens a new window for probing general relativity, accretion flow physics, and the launching sites of relativistic outflows. This project will study in detail these silhouettes against the background illumination by surrounding gas. The primary goals are to examine the sensitivity of features in the image to details of the accretion flow and of the jet physics, and to separate features which provide generic tests of general relativity. The simulations will use a general-relativistic code which incorporates ray-tracing, gas dynamics, and the relevant plasma physics. The second phase will examine how future observations could resolve the predicted images, in order to optimize the observing strategy and get the most scientific output from a given observing time.Testing General Relativity in the strong field limit is of great importance for fundamental physics, and black holes have long been known to attract a lot of interest from the general public. The black hole silhouette images from this work will be freely available to everyone via museums and the popular media through popular-level articles and movies.