Multiwavelength Studies of Galaxy Evolution

星系演化的多波长研究

基本信息

批准号：
RGPIN-2015-03851
负责人：
Webb, Tracy
金额：
$ 1.6万
依托单位：
McGill University
依托单位国家：
加拿大
项目类别：
Discovery Grants Program - Individual
财政年份：
2016
资助国家：
加拿大
起止时间：
2016-01-01 至 2017-12-31
项目状态：
已结题

来源：
https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=612612
关键词：
Multiwavelength Studies Galaxy Evolution

项目摘要

We live in a hierarchically organized universe. Over the past two decades, observational evidence and theoretical predictions have converged on a remarkably successful cosmological model -- cold Dark Matter with a Dark Energy component -- that describes the formation and evolution of structure at all scales through the gravitational amalgamation of matter. The backbone of this process is well understood, but the physics on the scales of stars, galaxies and galaxy clusters is very complex and controlled by multiple variables. This research program seeks to understand these processes and, in particular, the processes which formed galaxies like our own Milky Way. In hierarchical structure formation small objects (with masses of a million suns - small galaxies) form first after the Big Bang and then combine over time to form the largest objects seen today (reaching masses of a million billion stars). The act of coalescing galaxies is a violent and complex one which dramatically alters the physical state of the systems. Existing stars are redistributed, new populations of stars are produced in prodigious triggered bursts, and central supermassive black holes grow through infalling matter. Nevertheless, if we study galaxies in the universe today we see tight relationships between their properties which are indicative of underlying global processes. For example, the mass, shape and overall age of a galaxy is dependent on its local environment. Massive galaxies, that are elliptical and composed of old stars inhibit dense regions of the universe, with many other galaxies nearby. Moderate mass galaxies like our own Milky Way, with on-going star formation and spiral structure live in more isolated regions. My research program wants to understand the reasons behind trends such as these. Because light takes a finite time to travel, we see distant galaxies as they existed a long time ago. We use the world's largest telescopes to observe the most distant galaxies in the universe at a much earlier stage in their formation. By studying many galaxies at different times and in different environments we can piece together their evolutionary history. Using light emitted at different wavelengths we can measure the amount of stars a galaxy is composed of, the rate at which it is forming new stars, and whether it is growing a supermassive black hole at its center. Its physical shape often provides clues to the processes it is experiencing - such as a major galaxy merger event. We study large samples of galaxies in a quest to identify and understand global trends in their evolutionary phases. Occasionally, we discover a unique object that, if studied in detail can provide a wealth of information on a particular aspect of galaxy formation. By combining these two distinct approaches we can piece together a picture of how the rich and complex structure we see around us today was formed.

我们生活在一个分层组织的宇宙中，在过去的二十年里，观测证据和理论预测已经融合在一个非常成功的宇宙学模型上——带有暗能量成分的冷暗物质——它描述了所有尺度结构的形成和演化。这一过程的核心是众所周知的，但恒星、星系和星系团尺度上的物理学非常复杂，并且受到多个变量的控制。过程，特别是形成像我们银河系这样的星系的过程。在分层结构形成中，小物体（质量为一百万个太阳 - 小星系）首先在大爆炸后形成，然后随着时间的推移结合形成今天看到的最大物体（达到一百万亿颗恒星的质量）星系合并的行为。这是一种剧烈而复杂的现象，它极大地改变了现有恒星的物理状态，新的恒星群在巨大的触发爆发中产生，中心超大质量黑洞通过坠落的物质生长。然而，如果我们今天研究宇宙中的星系，我们会看到它们的属性之间的紧密关系，这些属性表明了潜在的全球过程。例如，星系的质量、形状和总体年龄取决于其当地环境。椭圆形且由老恒星组成的大质量星系会抑制宇宙的致密区域，而附近还有许多其他中等质量的星系。我们自己的银河系，不断的恒星形成和螺旋结构生活在更孤立的区域，我的研究项目想要了解这些趋势背后的原因。由于光的传播时间有限，我们可以使用世界上最大的望远镜，通过研究许多星系，在其形成的早期阶段观察到遥远的星系。在不同的时间和不同的环境中，我们可以利用不同波长发出的光拼凑出它们的演化历史，我们可以测量一个星系由恒星组成的数量、它形成新恒星的速度，以及它是否正在成长。其中心有一个超大质量黑洞。它的物理形状通常可以提供其正在经历的过程的线索，例如主要的星系合并事件。我们研究大量星系样本，旨在识别和理解其演化阶段的全球趋势，有时，我们会发现一个独特的物体，如果对其进行详细研究，可以通过结合这些物体来提供有关星系形成的特定方面的大量信息。我们可以通过两种不同的方法拼凑出一幅图画，了解我们今天周围看到的丰富而复杂的结构是如何形成的。