Towards an understanding of galaxy structure

了解星系结构

• 批准号: 227506-2009
• 负责人: Courteau, Stephane
• 金额: $ 3.86万
• 依托单位: Queen's University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2013
• 资助国家: 加拿大
• 起止时间: 2013-01-01 至 2014-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=523998
• 关键词: Towards; understanding; galaxy; structure

It is now believed that only 4% of the Universe exists in ordinary visible (baryonic) form, with another 23% in the form of non-radiating dark matter. The remainder permeates the Universe in the form of a dark energy. While the latter is a relatively new, speculative, concept, the gravitational presence of dark matter has been known for many decades. Dark matter is an integral part of any model of galaxy formation and evolution; still, we have yet to accurately map the distribution of visible and dark matter in any galaxy. This proposal is concerned with the measurement of visible and dark matter, and their interplay, as well as the distribution of stellar populations in galaxies. We are pursuing an ambitious program to measure the universal galaxy mass function as well as the scaling relations and stellar populations of galaxies using our multi-band imaging and spectroscopic data collected for Virgo cluster galaxies. The importance of the Virgo cluster in modern astrophysics can scarcely be overestimated as it is the dominant mass concentration and the largest collection of galaxies in the local Universe. If we are to understand the nature of galaxies, including their structural properties, mass/luminosity distribution, and dark matter content, the obvious route forward is through a high-sensitivity, multi-wavelength study of this testbed cluster and its constituent galaxies. Well-resolved optical and infrared images of the nearby Andromeda galaxy and integrated spectra of Milky Way globular clusters will also be used to calibrate stellar population models. Most of the data to achieve the goals of this proposal are either in place or guaranteed through approved legacy surveys (such as the Canada France Hawaii Telescope Next Generation Virgo Cluster Survey). We also use numerical simulations to model galaxy density profiles and refine galaxy mass estimators. Over the next five years, I plan to use this grant to supervise a minimum of five undergraduate students, seven master students, and two doctoral students. The graduate students in my group develop skills in observational, computational and theoretical astrophysics, as well as in research and teaching methods and public outreach.

现在人们认为，宇宙中只有4%以普通的可见(重子)形式存在，另有23%以非辐射暗物质的形式存在。其余的以暗能量的形式渗透到宇宙中。虽然后者是一个相对较新的、推测的概念，但暗物质的引力存在几十年来就已为人所知。暗物质是任何星系形成和演化模型中不可或缺的一部分；然而，我们还没有准确地绘制出可见物质和暗物质在任何星系中的分布。这一提议涉及可见物质和暗物质的测量，以及它们之间的相互作用，以及星系中恒星群的分布。我们正在实施一项雄心勃勃的计划，利用我们为室女座星系团收集的多波段成像和光谱数据，测量宇宙星系的质量函数以及星系的比例关系和恒星群。室女座星系团在现代天体物理学中的重要性怎么估计都不为过，因为它是当地宇宙中主要的质量集中和最大的星系集合。如果我们要了解星系的性质，包括它们的结构属性、质量/光度分布和暗物质含量，显而易见的前进路线是通过对这个试验台星系团及其组成星系进行高灵敏度、多波长的研究。附近仙女座星系的高分辨率光学和红外图像以及银河系球状星团的综合光谱也将用于校准恒星种群模型。实现这项提议目标的大部分数据要么已经到位，要么通过经批准的遗留调查(如加拿大、法国、夏威夷望远镜下一代处女座星系团调查)得到了保证。我们还使用数值模拟来模拟星系密度分布，并改进星系质量估计器。在接下来的五年里，我计划用这笔助学金至少指导五名本科生、七名硕士和两名博士生。我所在小组的研究生发展了观测、计算和理论天体物理学方面的技能，以及研究和教学方法以及公共宣传方面的技能。