The impact of magnetic fields on gas accretion onto supermassive black holes and AGN feedback: the next frontier of galaxy formation cosmological simu

磁场对超大质量黑洞气体吸积的影响和活动星系核反馈：星系形成宇宙学模拟的下一个前沿

• 批准号: 2753827
• 金额: --
• 依托单位: University of Oxford
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2022
• 资助国家: 英国
• 起止时间: 2022 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2753827
• 关键词: impact; magnetic; fields; gas; accretion

It is now well established that the main mechanism to fuel super massive black holes (SMBH) around which a sub-parsec sized accretion disk is spinning, is the magneto-rotational instability (Balbus & Hawley 1991). There also exists compelling observational evidence that SMBHs are ubiquitous and play an important role in regulating galaxy properties (mass, size, morphology) through extremely energetic AGN feedback events. However, cosmological galaxy formation simulations, by and large, ignore the effect of magnetic fields. Presumably this failure reflects the fact that star formation and stellar feedback, and SMBH formation, accretion and feedback, take place on extremely small, sub-galactic scales, making it a tremendous challenge for simulations to model them with reasonable accuracy whilst resolving the galaxy larger scale environment at the same time. Building on previous work within our group (Beckmann, Devriendt, Slyz 2018, Beckmann, Slyz & Devriendt 2019, Martin-Alvarez et al 2018, Katz, Martin-Alvarez et al 2019, Martin-Alvarez et al 2020), the aim of this DPhil project is to develop a fully magnetised implementation of SMBHs and AGN feedback in an explicit cosmological context. The DPhil project will have several steps starting from revisiting the classic Bondi-Hoyle-Lyttleton accretion model onto a point source to magnetize it, placing the black hole within an isolated galactic disk, adding AGN feedback to it before finally moving to the cosmological environment.The student will also develop a model for galaxy synchrotron emission based on the post-processing of these galactic and cosmological MHD simulations, in a view to produce realistic mock observational data for the coming Square Kilometer Array instrument and its precursors (in interaction with the radio astronomy observational group at Oxford centred around Prof. Jarvis).

现在已经确定，为超大质量黑洞（SMBH）提供燃料的主要机制是磁旋转不稳定性（Balbus & Hawley 1991），亚秒差距大小的吸积盘围绕着该黑洞旋转。还有令人信服的观测证据表明，超大质量黑洞无处不在，并且通过极其活跃的活动星系核反馈事件在调节星系特性（质量、大小、形态）方面发挥着重要作用。然而，宇宙学星系形成模拟总体上忽略了磁场的影响。据推测，这种失败反映了这样一个事实，即恒星形成和恒星反馈，以及超大质量黑洞的形成、吸积和反馈，都发生在极小的亚银河尺度上，这使得模拟以合理的精度对其进行建模，同时解析更大的星系是一个巨大的挑战。同时缩放环境。基于我们小组之前的工作（Beckmann, Devriendt, Slyz 2018，Beckmann, Slyz & Devriendt 2019，Martin-Alvarez et al 2018，Katz, Martin-Alvarez et al 2019，Martin-Alvarez et al 2020），本次研究的目标DPhil 项目旨在以明确的方式开发 SMBH 和 AGN 反馈的完全磁化实施宇宙学背景。 DPhil 项目将分为几个步骤，首先是重新审视经典的 Bondi-Hoyle-Lyttleton 吸积模型，将其磁化到点源上，将黑洞放置在孤立的银盘内，向其添加 AGN 反馈，然后最终转移到宇宙环境中。学生还将基于这些星系和宇宙 MHD 模拟的后处理，开发一个星系同步加速器发射模型，以期生成真实的模拟观测数据即将推出的平方公里阵列仪器及其前身（与以贾维斯教授为中心的牛津射电天文学观测小组互动）。