Galaxy Evolution in Dense Environments

密集环境中的星系演化

• 批准号: RGPIN-2020-05981
• 负责人: Parker, Laura
• 金额: $ 2.99万
• 依托单位: McMaster University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2021
• 资助国家: 加拿大
• 起止时间: 2021-01-01 至 2022-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=740956
• 关键词: Galaxy; Evolution; Dense; Environments

New telescope facilities and dedicated surveys have resulted in enormous progress in extra-galactic astronomy and cosmology over the past two decades. While we have now tightly constrained many of the fundamental cosmological parameters that describe our universe, there are still exciting unanswered questions concerning the formation and evolution of galaxies and larger structures. In my group we are interested in the evolution of galaxies and the connection between galaxies and their host environments. Many galaxies in the local universe do not live in isolation, but are clustered into systems called galaxy groups and clusters. In order to probe galaxy evolution in groups and clusters we will use a combination of multi-wavelength observations and state-of-the-art simulations. Galaxy populations are largely bimodal in their properties, with some galaxies being red and round and some galaxies being blue, star-forming, with disk-like shapes. There is evidence that over time galaxies transition from being blue and star-forming to red and passively evolving, but the precise mechanisms that drive this evolution are not well understood. Quenching is the process of shutting down star formation, which causes galaxies to transition from blue to red. We will study quenching by correlating observed galaxy properties with the properties of their host environment, including the host mass, host dynamical state, and the properties of X-ray gas that permeates groups and clusters. This proposal concentrates on three specific projects, which are an exciting new direction for us, because we combine cutting-edge observations and simulations to understand galaxy evolution in dense environments: 1) Study nearby and distant galaxy clusters with X-ray, optical and radio data to determine which quenching mechanisms are important at different epochs. 2) Using optical and radio data study the locations of quenching within individual galaxies and determine if quenching is dominated by internal or environmental processes for different galaxy populations. 3) Use simulations to study the dependence of galaxy evolution on the assembly history of their host halos. Through a combination of observations and simulations, we are ideally poised to understand the diverse ways in which galaxies evolve in different environments over cosmic time.

在过去的二十年里，新的望远镜设施和专门的调查使河外天文学和宇宙学取得了巨大进步。虽然我们现在已经严格限制了描述宇宙的许多基本宇宙学参数，但关于星系和更大结构的形成和演化，仍然存在令人兴奋的未解答问题。在我的小组中，我们对星系的演化以及星系与其宿主环境之间的联系感兴趣。本地宇宙中的许多星系并不是孤立存在的，而是聚集成称为星系群和星系团的系统。为了探索星系群和星系团的演化，我们将结合使用多波长观测和最先进的模拟。星系群的特性在很大程度上是双峰的，一些星系是红色的圆形的，一些星系是蓝色的，正在形成恒星，具有盘状形状。有证据表明，随着时间的推移，星系从蓝色和恒星形成转变为红色并被动演化，但驱动这种演化的确切机制尚不清楚。淬灭是停止恒星形成的过程，导致星系从蓝色转变为红色。我们将通过将观测到的星系特性与其宿主环境的特性（包括宿主质量、宿主动力学状态以及渗透到星系团和星团的 X 射线气体的特性）相关联来研究猝灭。 该提案集中于三个具体项目，这对我们来说是一个令人兴奋的新方向，因为我们结合了尖端观测和模拟来了解密集环境中的星系演化：1）利用X射线、光学和无线电数据研究附近和遥远的星系团，以确定哪些猝灭机制在不同时期很重要。 2) 使用光学和射电数据研究各个星系内猝灭的位置，并确定不同星系群体的猝灭是否由内部或环境过程主导。 3）利用模拟研究星系演化对其宿主晕组装历史的依赖性。 通过观测和模拟的结合，我们完全有能力了解宇宙时间内星系在不同环境中演化的不同方式。