A Multiwavelength Study of the Physics of the Intracluster Medium, Its Multiple Phases and AGN Feedback

簇内介质物理、多相和 AGN 反馈的多波长研究

基本信息

批准号：
RGPIN-2017-04939
负责人：
Baum, Stefi
金额：
$ 1.53万
依托单位：
University of Manitoba
依托单位国家：
加拿大
项目类别：
Discovery Grants Program - Individual
财政年份：
2020
资助国家：
加拿大
起止时间：
2020-01-01 至 2021-12-31
项目状态：
已结题

来源：
https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=711304
关键词：
Multiwavelength Study Physics Intracluster Medium

项目摘要

Clusters of galaxies are the largest gravitationally bound structures in the Universe. Baryonic matter, unlike the dominant dark matter, is accessible to direct observations. It is found within individual galaxies as stars and as a hot tenuous gas, dubbed the ICM, filling the space between galaxies. As the ICM cools it radiates in the x-ray part of the spectrum. Left unattended it will continue to cool, radiating in the ultraviolet, optical, and infrared. Ultimately the gas should cool to tens of degrees and be bound in giant molecular gas clouds that collapse to form stars. At the center of a rich cluster sits a massive bright elliptical galaxy, the Brightest Cluster Galaxy (BCG), which houses a super-massive Black Hole (SMBH) at its nucleus. It is believed that the SMBH re-supplies energy to the ICM as some of the cold gas that condenses from the ICM falls onto an accretion disk around the Black Hole, ultimately adding to the mass of the Black Hole and fuelling the ejection of a powerful outflow. This outflow carries energy, magnetic fields, and relativistic electrons into the ICM where it can re-supply energy lost through radiation. Recent observations with radio and X-ray telescopes have provided new high quality images showing the outflow excavating cavities and driving pressure waves into the ICM. Thus it is clear a complex interplay exists between cooling and heating, inflow and outflow, accretion and growth. The same physical processes operating in clusters today likely occurred during galaxy formation 5-10 billion years ago. Astronomers believe that the growth of the galaxy and its central black hole are coupled via feedback process. The feedback between the medium, galaxy growth, and the central black hole must operate over billions of years, and on size scales from parsecs to hundred of thousands of parsecs. Thus, the ICM is a dynamic place where heating and cooling processes vie for dominance, super-massive black holes grow at the centers of galaxies, and an uneasy equilibrium is maintained. The major objective of this work is to uncover how feedback mechanisms operate in the centers of clusters by developing a detailed understanding of the physical processes at work. With my NSERC Discovery grant, I will conduct a multi-wavelength observational study of nearby clusters, to map the spatial, thermal, and temporal evolution of the baryonic matter, determine the system energetics, and identify the dominant feedback loops at play. Working with 4 HQP from high school through postdoc, we will have assembled a detailed picture of the spatial distribution, kinematics, mass content, and energetics of each phase of the baryonic matter in these complex systems. Impact: this work will create the information that we and other astronomers use to develop our understanding of the feedback mechanisms and macro-evolutionary laws that govern cluster and galaxy evolution.

星系团是宇宙中最大的引力束缚结构。与占主导地位的暗物质不同，重子物质可以直接观测。它以恒星和炽热的稀薄气体（称为 ICM）的形式存在于各个星系中，充满了星系之间的空间。当 ICM 冷却时，它会辐射光谱的 X 射线部分。如果无人看管，它将继续冷却，并辐射紫外线、光学和红外线。最终，气体应该冷却到几十度，并被束缚在巨大的分子气体云中，这些分子气体云会坍塌形成恒星。在一个丰富星团的中心坐落着一个巨大的明亮椭圆星系，即最亮星团星系（BCG），其核心有一个超大质量黑洞（SMBH）。人们相信，当 ICM 凝结的一些冷气体落到黑洞周围的吸积盘上时，SMBH 会向 ICM 重新提供能量，最终增加黑洞的质量并为喷射出强大的物质提供燃料。外流。这种流出将能量、磁场和相对论电子带入 ICM，在那里它可以重新供应因辐射而损失的能量。最近使用射电和 X 射线望远镜进行的观测提供了新的高质量图像，显示了流出物挖掘空腔并将压力波驱动到 ICM 的情况。因此，很明显，冷却和加热、流入和流出、吸积和增长之间存在着复杂的相互作用。今天在星团中运行的相同物理过程很可能发生在 5-100 亿年前的星系形成过程中。天文学家认为，星系及其中心黑洞的生长是通过反馈过程耦合的。介质、星系生长和中心黑洞之间的反馈必须运行数十亿年，大小范围从秒差距到数十万秒差距。因此，ICM是一个动态的地方，加热和冷却过程争夺主导地位，超大质量黑洞在星系中心生长，并维持着不稳定的平衡。这项工作的主要目标是通过详细了解工作中的物理过程来揭示反馈机制如何在集群中心运作。凭借我的 NSERC 发现资助，我将对附近星团进行多波长观测研究，绘制重子物质的空间、热和时间演化图，确定系统能量学，并确定起作用的主要反馈回路。我们将与从高中到博士后的 4 个 HQP 合作，收集这些复杂系统中重子物质每个相的空间分布、运动学、质量含量和能量学的详细图片。影响：这项工作将创建我们和其他天文学家用来加深我们对控制星团和星系演化的反馈机制和宏观演化定律的理解的信息。