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

Greg Salvesen被授予美国国家科学基金会天文学和天体物理学博士后奖学金，在加州大学圣巴巴拉分校开展研究和教育项目。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 XRBs），它由一个黑洞以伴星发出的x射线气体盘为食组成。了解黑洞XRBs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。由于黑洞XRBs被认为是超大质量黑洞的缩小版本，并且在天文学家可以获得的时间尺度上表现出变化，因此它们是研究黑洞周围物质如何吸积的理想实验室。除了这项工作，Salvesen还将创建一个网站，展示已经转换成声音样本的真实天文数据，他还将开发讲习班，通过声音向有视觉障碍或英语水平有限的K-12学生传达课堂上的天文学概念。Salvesen将对强磁化吸积盘进行数值模拟，以计算BH XRBs的两个直接可观测量：(1)受不同强度和几何形状的磁场影响的吸积盘发出的光谱，以及吸积盘变异性产生的准周期振荡；(2)磁驱动盘风吸收的光谱，并在诊断探针中表现出来（例如，高电离原子的光谱线）。然后，Salvesen将把模拟结果与BH-XRBs观测到的特性进行比较，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还将创建每月天文之声（ASOM）网站，并开发“发声”研讨会，向视力受损或学习英语的K-12学生传达基本的天文学概念。

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.