Environmental Drivers of Galaxy Evolution

星系演化的环境驱动因素

• 批准号: PP/E004423/1
• 负责人: Meghan Gray
• 金额: $ 55.52万
• 依托单位: University of Nottingham
• 依托单位国家: 英国
• 项目类别: Fellowship
• 财政年份: 2008
• 资助国家: 英国
• 起止时间: 2008 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=PP%2FE004423%2F1
• 关键词: Environmental; Drivers; Galaxy; Evolution

Throughout history, our view of the Universe has been formed by observations made of those parts that glow in the dark. We see wonderfully diverse types of galaxies: some are grand spiral disks full of stars, gas, and dust; others are collections of old stars bound together in a shape resembling a rugby ball. While spiral galaxies are often lit up by the birth of hot young stars, the older, redder elliptical galaxies have left their youthful bursts of star formation well behind them. We also observe that the force of gravity can draw galaxies together in groups of tens or even hundreds to form structures we call galaxy clusters. In these crowded regions of the Universe, galaxies orbit about each other like a swarm of bees, held together by their mutual gravitational pull. In recent years, however, we have begun to gather proof that the glowing stars, gas and galaxies that we see represent only a small fraction of the total mass present. In reality, we know that most of the Universe is composed of a mysterious `dark matter' that is invisible to our standard telescopes. However, we know it is there because of the gravitational pull it exerts on things that we can see. The goal of my research is to trace exactly how and where this dark matter is spread throughout the Universe, and to discover how it is linked to the galaxies that are rooted in it. To reveal the dark side of the Universe I use a powerful tool called 'gravitational lensing'. Gravitational lensing works on the principle from Einstein's theory of General Relativity that massive objects warp the spacetime around them. This means that everything -- even light -- feels the pull of gravity. By measuring how much light is distorted or bent as it passes around a massive object, we can actually weigh that object...even if we can't see it directly. Much of the research I am proposing here focuses on a particularly interesting region of the Universe known as the A901/902 Supercluster. This is an enormous structure spanning more than 15 million lightyears. I plan to use observations from major telescopes around the world and in space to carefully peel apart this supercluster layer by layer: images from the Hubble Space Telescope to determine where the galaxies are and what they look like, gravitational lensing to map the dark matter that forms the skeleton of the supercluster, and X-ray satellites to trace the glowing reservoirs of hot X-ray gas that lie in the cluster cores. My aim is to understand how these ingredients interact, and in particular how the galaxies are affected by living there. Do the galaxies evolve and change over their lifetime because they live in such crowded conditions? We know that the galaxies in rich clusters generally look quite different from those we see in isolated regions of space. Just as life in the big city can be very different from rural life, the pace of life in a galaxy cluster is for the most part much faster and more violent. Galaxies entering this environment might fall prey to a number of environmental effects that could be strip them of their fuel supply (meaning they will be unable to form more stars in the future) and change their shapes. This could happen in several ways: by galaxies plunging through large central reservoirs of hot gas, by the gravitational force of the dark matter, or by high speed collisions or close encounters with other galaxies. What we don't know right now is which, if any, of these physical processes are responsible for transforming galaxies as they are absorbed into clusters. That's why the observations I am making are important: with them, I am able to look in detail at even the faintest galaxies in the supercluster and try to trace exactly when and how these transformations occur. Putting all the pieces of the puzzle together will help us to understand how galaxies form and evolve in the Universe, and how they come to form the amazing structures we observe today.

纵观历史，我们对宇宙的看法是通过观察那些在黑暗中发光的部分形成的。我们看到了各种各样的星系：有些是巨大的螺旋盘，充满了恒星、气体和尘埃;有些是古老恒星的集合，它们以类似橄榄球的形状结合在一起。当螺旋星系经常被炽热的年轻恒星的诞生所照亮时，更老、更红的椭圆星系已经把它们年轻的星星形成的爆发远远抛在身后。我们还观察到，引力可以将星系以数十甚至数百个为一组吸引到一起，形成我们称之为星系团的结构。在宇宙中这些拥挤的区域，星系就像一群蜜蜂一样围绕着彼此旋转，通过它们之间的相互引力聚集在一起。然而，近年来，我们已经开始收集证据，证明我们看到的发光的恒星，气体和星系只占总质量的一小部分。事实上，我们知道宇宙的大部分是由一种神秘的“暗物质”组成的，我们的标准望远镜是看不见的。然而，我们知道它在那里，因为它施加在我们可以看到的东西上的引力。我的研究目标是精确地追踪暗物质在宇宙中的分布方式和位置，并发现它与植根于其中的星系之间的联系。为了揭示宇宙的黑暗面，我使用了一种强大的工具，称为“引力透镜”。引力透镜的原理来自爱因斯坦的广义相对论，即大质量物体会扭曲周围的时空。这意味着一切，甚至光，都能感受到引力的拉力。通过测量光在经过一个大质量物体时被扭曲或弯曲的程度，我们实际上可以称量这个物体的重量。即使我们不能直接看到它。我在这里提出的大部分研究都集中在宇宙中一个特别有趣的区域，即A901/902超星系团。这是一个跨越1500多万光年的巨大结构。我计划利用世界各地和太空中的主要望远镜的观测结果，一层一层地仔细剥离这个超星系团：哈勃太空望远镜的图像，以确定星系的位置和它们的样子，引力透镜映射形成超星系团骨架的暗物质，X射线卫星追踪位于星系团核心的炽热X射线气体的发光水库。我的目标是了解这些成分是如何相互作用的，特别是星系是如何受到生活的影响的。星系在它们的一生中会进化和改变吗？因为它们生活在如此拥挤的环境中。我们知道，在丰富的星系团中的星系通常看起来与我们在太空孤立区域中看到的星系大不相同。就像大城市的生活可能与乡村生活大不相同一样，星系团中的生活节奏在很大程度上要快得多，也更激烈。进入这种环境的星系可能会成为许多环境影响的牺牲品，这些环境影响可能会剥夺它们的燃料供应（这意味着它们将来无法形成更多的恒星）并改变它们的形状。这可能以几种方式发生：星系穿过热气体的大型中央水库，暗物质的引力，或者与其他星系的高速碰撞或近距离接触。我们现在不知道的是，这些物理过程中的哪一个，如果有的话，是负责转变星系，因为它们被吸收成星系团。这就是为什么我所做的观测是重要的：有了它们，我能够详细地观察超星系团中最微弱的星系，并试图准确地追踪这些转变何时以及如何发生。把所有的拼图放在一起将有助于我们理解星系如何在宇宙中形成和演化，以及它们如何形成我们今天观察到的惊人结构。

项目成果

STAGES: the Space Telescope A901/2 Galaxy Evolution Survey

阶段：太空望远镜 A901/2 星系演化巡天

• DOI: 10.1111/j.1365-2966.2008.14259.x
• 发表时间: 2008-11
• 期刊: Monthly Notices of the Royal Astronomical Society
• 影响因子: 4.8
• 作者: H?u?ler, Boris;Bell, Eric F.;McIntosh, Daniel H.;Guo, Yicheng;Caldwell, John A. R.
• 通讯作者: Caldwell, John A. R.

INTERACTING GALAXIES IN THE A901/902 SUPERCLUSTER WITH STAGES

A901/902 超星系团中星系与阶段的相互作用

• DOI: 10.1088/0004-637x/705/2/1433
• 发表时间: 2009
• 期刊: The Astrophysical Journal
• 作者: Heiderman A

Tully-Fisher analysis of the multiple cluster system Abell 901/902

• DOI: 10.1051/0004-6361/201321561
• 发表时间: 2013-04
• 期刊: Astronomy and Astrophysics
• 影响因子: 6.5
• 作者: Benjamin Bosch;A. Bohm;C. Wolf;A. Arag'on-Salamanca;B. Ziegler;M. Barden;M. Gray;M. Balogh;K. Meisenheimer;S. Schindler

OMEGA - OSIRIS Mapping of Emission-line Galaxies in A901/2 - I. Survey description, data analysis, and star formation and AGN activity in the highest density regions

OMEGA - A901/2 中发射线星系的 OSIRIS 测绘 - I. 勘测描述、数据分析以及最高密度区域中的恒星形成和 AGN 活动

• DOI: 10.1093/mnras/stv779
• 发表时间: 2015
• 期刊: Monthly Notices of the Royal Astronomical Society
• 影响因子: 4.8
• 作者: Chies-Santos A

Relating basic properties of bright early-type dwarf galaxies to their location in Abell 901/902

将明亮的早期型矮星系的基本特性与其在阿贝尔 901/902 中的位置联系起来

• DOI: 10.1051/0004-6361/200912716
• 发表时间: 2009-11
• 期刊: Astronomy & Astrophysics
• 影响因子: 6.5
• 作者: Peng C. Y.;Jahnke K.;van Kampen E.;Meisenheimer K.;Balogh M.;Heiderman A.;Wolf C.;Barden M.;Sanchez S. F.;Gray M. E.;Caldwell J. A. R.;Jogee S.;Zheng X. Z.;Böhm A.;Taylor A.;Heymans C.;Häussler B.;Barazza F. D.;Bell E. F.;Bacon D.;Lane K
• 通讯作者: Lane K