Magnetically Supported Accretion Disks Around Black Holes: Observational Diagnostics from Numerical Simulations

Greg Salvesen被授予NSF天文学和天体物理学博士后奖学金，在圣巴巴拉的加州大学开展研究和教育计划。Salvesen将进行先进的数值模拟，以了解强磁场如何影响黑洞X射线双星（BH XRB），其中包括一个黑洞从伴星星星的X射线发射气体盘上进食。理解BH XRB也是了解其他类型黑洞的关键。几乎每个星系（包括我们自己的星系）的中心都有一个被气体盘包围的超大质量黑洞，但超大质量黑洞很难理解，因为它们在我们的一生中几乎没有变化。由于BH XRB被认为是超大质量黑洞的缩小版本，并且在天文学家可以访问的时间尺度上表现出变化，因此它们是研究物质如何在黑洞周围吸积的理想实验室。除此之外，Salvesen还将创建一个网站，展示已转换为声音样本的真实的天文数据，他还将开发研讨会，通过声音向有视力障碍或英语水平有限的K-12学生传达课堂天文学概念。Salvesen将进行强磁化吸积盘的数值模拟，以计算BH XRB的两个直接可观测量：（1）由受到各种强度和几何形状的磁场的吸积盘发射的光的光谱，以及由吸积盘可变性产生的准周期振荡;以及（2）由磁驱动盘风吸收的光的光谱，并且在诊断探针中表现出来（例如，高度电离原子的光谱线）。然后，Salvesen将把模拟结果与观测到的BH-XRB性质进行比较，以确定这些物体的发射和吸收光谱是否可以用来理解强磁场对黑洞吸积盘的影响。Salvesen还将创建天文学每月之声（ASOM）网站，并开发“发声”研讨会，向视障或英语学习K-12学生传达基本天文学概念。

Greg Salvesen is awarded an NSF Astronomy and Astrophysics Postdoctoral Fellowship to carry out a program of research and education at the University of California, Santa Barbara. Salvesen will perform advanced numerical simulations to understand how strong magnetic fields influence black hole X-ray Binaries (BH XRBs), which consist of a black hole feeding on a disk of X-ray emitting gas from a companion star. Understanding BH XRBs is key to learning about other types of black holes as well. The center of nearly every galaxy (including our own) hosts a supermassive black hole surrounded by a disk of gas, but supermassive black holes are very difficult to understand because they change very little over our lifetimes. Because BH XRBs are thought to be scaled down versions of supermassive black holes, and exhibit changes on timescales accessible to astronomers, they are ideal laboratories for studying how material accretes around a black hole. Alongside this work, Salvesen will create a website featuring real astronomical data that have been converted into sound samples, and he will develop workshops to convey classroom astronomy concepts through sound to K-12 students with visual impairments or limited English proficiency.Salvesen will undertake numerical simulations of strongly magnetized accretion disks to calculate two direct observable quantities of BH XRBs: (1) the spectrum of light emitted by an accretion disk subjected to magnetic fields of various strengths and geometries, as well as quasi-periodic oscillations produced by accretion disk variability; and (2) the spectrum of light absorbed by magnetically driven disk winds, and manifested in diagnostic probes (e.g., spectral lines of highly ionized atoms). Salvesen will then compare the simulations with the observed properties of BH-XRBs to determine if the emission and absorption spectra of these objects can be used to understand the influence of strong magnetic fields on black hole accretion disks. Salvesen will also create the Astronomy Sound of the Month (ASOM) website and develop "sonification" workshops to convey basic astronomy concepts to visually impaired or English-language learning K-12 students.