Modelling Accretion Disk Winds

吸积盘风建模

• 批准号: 2750006
• 金额: --
• 依托单位: University of Southampton
• 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-2750006
• 关键词: Modelling; Accretion; Disk; Winds

All quasars are powered by the same central engine: a supermassive black hole that is surrounded and fed by a luminous accretion disk. Approximately 15% of all quasars exhibit clear evidence for powerful outflows driven from these disks, in the form of broad, blue-shifted absorption lines. However, these so-called "broad absorption line quasars" (BALQSOs) are just the tip of the iceberg: since disk-driven winds cannot be spherical, BALQSOs are just the sub-set of quasars viewed at a particularly favourable orientation. In reality, *all* quasars are likely to drive such winds. This is important, because these outflows provide a key feedback mechanism: they can remove significant amounts of mass, energy and angular momentum from the quasar and inject it into the surrounding (inter-)galactic medium. However, despite their importance, we know almost nothing about these accretion disk winds. For example, the geometry, kinematics, and even the basic driving mechanism responsible for launching them are still basically unknown.The aim of this PhD project will be to remedy this situation by modelling the wind-formed features in the spectra of quasars. This work will be carried out in the context of an established collaboration (which includes two other PhD students and one postdoctoral fellow at Southampton) and will use an existing, state-of-the-art Monte Carlo radiative transfer code. The ultimate goal we are pursuing is to determine the fundamental parameters of quasar accretion disk winds and thus shed light on how they regulate the fueling of supermassive black holes and the feedback of energy into their environment. In addition, we aim to shed light on quasar unification: is it possible that *most* observational signatures we associate with (even non-BAL) quasars are actually shaped by disk winds?

所有类星体都由同一个中央引擎提供动力：一个超大质量黑洞，它被一个发光的吸积盘包围并提供能量。大约15%的类星体显示出明显的证据，证明这些圆盘以宽阔的蓝移吸收线的形式驱动着强大的外流。然而，这些所谓的“宽吸收线类星体”(BALQSO)只是冰山一角：由于圆盘驱动的风不可能是球形的，BALQSO只是以特别有利的方位观察的类星体的子集。事实上，“所有”类星体都有可能驱动这样的风。这一点很重要，因为这些外流提供了一个关键的反馈机制：它们可以从类星体中移除大量的质量、能量和角动量，并将其注入周围的(星系间)介质中。然而，尽管它们很重要，我们对这些吸积盘风几乎一无所知。例如，负责发射它们的几何学、运动学，甚至是基本的驱动机制仍然是未知的。这个博士项目的目的将是通过模拟类星体光谱中的风形成特征来纠正这种情况。这项工作将在已建立的合作范围内进行(包括南安普顿的另外两名博士生和一名博士后研究员)，并将使用现有的、最先进的蒙特卡罗辐射转移程序。我们追求的最终目标是确定类星体吸积盘风的基本参数，从而阐明它们是如何调节超大质量黑洞的燃料和能量反馈到其环境中的。此外，我们的目标是阐明类星体的统一：我们与类星体(即使是非BAL类星体)相关的*大多数*观测信号是否可能实际上是由圆盘风塑造的？