The Milky Way and its neighbours in the era of large surveys

大巡天时代的银河系及其邻居

• 批准号: RGPIN-2018-03853
• 负责人: McConnachie, Alan
• 金额: $ 3.64万
• 依托单位: University of Victoria
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2018
• 资助国家: 加拿大
• 起止时间: 2018-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=659190
• 关键词: Milky; Way; its; neighbours; era

Recent maps of the distribution of stars in the outskirts of the Milky Way and Andromeda galaxies are a startling visual demonstration of the immense complexity of galaxies at large distances from the centre. They show dwarf galaxies, as well as stellar streams and other diffuse structures, as part of the same ``galactic ecosystem'', whereby interactions between galaxies and the merging of smaller galaxies into larger galaxies appear to represent part of the life-cycle of these objects. New and upcoming facilities - most immediately Gaia, as well as LSST and TMT - provide remarkable opportunities for qualitative progress in better understanding this ecosystem, the role of dwarf galaxies within it, and its consistency (or otherwise) with the cosmological paradigm. A core goal of my research is to exploit opportunites presented by Gaia, and to prepare for these upcoming scientific, technological and data opportunities through a research program centered around graduate student training. Specifically, my students will use large survey datasets for which I am PI, and that are uniquely taylored to specific studies of the nearest galaxies that cannot otherwise be addressed by the international community. ***My research program straddles aspects of stellar astrophysics, galaxy evolution, and cosmology. It is well established that the large scale structure of the Universe is well described by the prevailing cosmological paradigm, and it indicates that mass in the Universe is "dark" (i.e., it does not emit electromagnetic radiation). We infer its presence, however, by its gravitational influence on luminous matter, and all galaxies are expected to form within dark matter concentrations called "halos". The onus is now on researchers to test this paradigm on smaller spatial scales for which the theory was not originally developed. Here, there are well-founded, testable, predictions, but unravelling these from the complex physics of galaxy formation is observationally very difficult. The nearest galaxies offer the best opportunities for many of the relevant observations. For example, galaxy halos are intrinsically very faint, since despite being home to most of the mass of the galaxy they have very few stars with which we can hope to trace the underlying dark matter. Further, it is only for the nearby Universe that we can access the smallest ("dwarf") galaxies that provide some of the most significant challenges for the cosmological paradigm, and which appear to be the most dark-matter dominated systems that exist. I lead several programs that are aimed at providing essential data on the properties of dwarf galaxies and on the properties of galaxy halos. My overall research program is centred around graduate student training and utilizes high level access to these internationally competitive observational datasets and facilities to advance this burgeouning field.

最近在银河系和仙女座星系郊区恒星分布的地图是令人震惊的视觉示范，表明了距中心大距离的星系的巨大复杂性。它们显示了矮星系，以及恒星的流和其他弥漫性结构，作为同一``银河生态系统''的一部分，在该'中，星系与较小星系之间的相互作用似乎代表了这些物体生命周期的一部分。新的和即将到来的设施 - 大多数立即盖亚以及LSST和TMT-为更好地理解该生态系统的作用，其中矮星系的作用以及与宇宙学范式的一致性（或其他）为定性进步提供了显着的机会。我的研究的核心目标是利用盖亚（Gaia）提出的机会，并通过以研究生培训为中心的研究计划为即将到来的科学，技术和数据机会做准备。具体来说，我的学生将使用我是PI的大型调查数据集，并且对最近的国际社会无法解决的最近星系的特定研究非常有用。 ***我的研究计划跨越了恒星天体物理学，星系进化和宇宙学的各个方面。众所周知，宇宙的大规模结构由盛行的宇宙学范式很好地描述，它表明宇宙中的质量是“黑暗”（即，它不会发出电磁辐射）。但是，我们通过其对发光物质的重力影响推断出它的存在，并且所有星系都预计将在称为“ Halos”的暗物质浓度内形成。现在，研究人员正在责任测试该范式对该理论最初并非开发的较小空间量表。在这里，有充分的基础，可测试的预测，但是从星系形成的复杂物理学中阐明这些，在观察上非常困难。最近的星系为许多相关观察提供了最佳机会。例如，星系光环在本质上非常微弱，因为尽管是大多数星系质量的家园，但它们的恒星很少，我们希望可以追踪下面的暗物质。此外，只有对于附近的宇宙，我们才能访问最小的（“矮人”）星系，从而为宇宙学范式提供了一些最重要的挑战，并且似乎是存在的最暗的主导系统。我领导的几个程序旨在提供有关矮星系属性和星系晕特性的基本数据。我的整体研究计划以研究生培训为中心，并利用对这些国际竞争激烈的观察数据集和设施的高水平访问权限，以推动这一新兴领域。