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Testing the cold dark matter paradigm with dwarf galaxies and stellar streams in Gaia and LSST

用盖亚和 LSST 中的矮星系和恒星流测试冷暗物质范式

基本信息

批准号：
ST/N004493/1
负责人：
Sergey Koposov
金额：
$ 53.97万
依托单位：
University of Cambridge
依托单位国家：
英国
项目类别：
Fellowship
财政年份：
2016
资助国家：
英国
起止时间：
2016 至无数据
项目状态：
已结题

来源：
https://gtr.ukri.org/projects?ref=ST%2FN004493%2F1
关键词：
Testing cold dark matter paradigm

项目摘要

The first evidence that galaxies contain large amount of invisible dark matter has been revealed more than 50 years ago. Since then we learned that dark matter is more than five times more abundant than ordinary matter in the universe and that it is one of the key drivers of galaxy evolution, as all the galaxies including the Milky Way are embedded inside large dark matter halos. However, we still do not know much about the nature of dark matter particles and their distribution in the Milky Way and other galaxies. Also while the current cosmological paradigm based on cold dark matter (Lambda CDM) is very successful in reproducing a vast range of observations, the predictions of this model on small scales remain very poorly tested.The goal of my research is to use our galactic neighbourhood, such as dwarf galaxies, orbiting around the Milky Way and stellar streams (streams of stars produced by satellites tidally disrupted by the Milky Way) to test Lambda CDM and learn more about dark matter. In particular I plan to use data from the Gaia satellite and other large surveys of the sky such as LSST to find and characterize stellar streams. The search and analysis of stellar streams will help me understand the past history of the Milky Way formation. The modelling of positions and velocities of stellar streams will tell me about the distribution of mass inside our Galaxy and in particular the distribution of dark matter; the analysis of the stellar density distribution inside stellar streams will allow me to detect small gravitational perturbations produced by small dark matter halos. I also plan to develop new methods to search for dwarf galaxies orbiting the Milky Way in the Gaia data. This should allow me to detect galaxies of even lower mass than before and located even closer to the Sun, thus enabling studies of the dark matter at small scales and searches for dark matter annihilation signal. Finally, I also plan to tackle a problem that is extremely important for the searches of dwarf galaxies and stellar streams in large imaging surveys of the sky: star-galaxy separation. With many deep imaging surveys ongoing and LSST survey around the corner, our ability of separating faint stars from faint galaxies is becoming the main limiting factor for the studies of faint structures around the Milky Way.

50多年前，人们首次发现了星系中含有大量看不见的暗物质的证据。从那时起，我们了解到暗物质的含量是宇宙中普通物质的五倍多，它是星系演化的关键驱动力之一，因为包括银河系在内的所有星系都镶嵌在巨大的暗物质晕中。然而，我们对暗物质粒子的性质及其在银河系和其他星系中的分布仍然知之甚少。此外，虽然目前基于冷暗物质（Lambda CDM）的宇宙学范式在再现大量观测结果方面非常成功，但该模型在小尺度上的预测仍然非常缺乏验证。我的研究目标是利用我们的星系邻居，如矮星系，围绕银河系和恒星流（由被银河系潮汐破坏的卫星产生的恒星流）来测试Lambda CDM并了解更多关于暗物质的信息。特别是，我计划使用盖亚卫星和其他大型天空调查（如LSST）的数据来发现和描述恒星流。对恒星流的搜索和分析将帮助我了解银河系形成的历史。对恒星流位置和速度的建模将告诉我银河系内部的质量分布，尤其是暗物质的分布；对恒星流内部恒星密度分布的分析将使我能够探测到由小暗物质晕产生的小引力扰动。我还计划开发新的方法，在盖亚数据中寻找围绕银河系运行的矮星系。这将使我能够探测到比以前质量更低、距离太阳更近的星系，从而使我们能够在小尺度上研究暗物质，并寻找暗物质湮灭信号。最后，我还计划解决一个问题，这个问题对于在大型天空成像调查中搜索矮星系和恒星流非常重要：恒星-星系分离。随着许多深度成像调查的进行和LSST调查即将到来，我们从微弱星系中分离暗淡恒星的能力正在成为研究银河系周围微弱结构的主要限制因素。

项目成果

期刊论文数量（10）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Unmixing the Galactic halo with RR Lyrae tagging

DOI：
10.1093/mnras/sty615
发表时间：
2017-11
期刊：
Monthly Notices of the Royal Astronomical Society
影响因子：
4.8
作者：
V. Belokurov;A. Deason;Sergey E. Koposov;M. Catelán;D. Erkal;A. Drake;N. Evans
通讯作者：
V. Belokurov;A. Deason;Sergey E. Koposov;M. Catelán;D. Erkal;A. Drake;N. Evans

The Gaia-ESO Survey: Hydrogen lines in red giants directly trace stellar mass

盖亚-欧洲南方天文台巡天：红巨星中的氢线直接追踪恒星质量