Extragalactic Globular Clusters and Galaxy Formation

brodieglobular star clusters brodieglobular clusters brodieglobular星团brodieglobular星团brodieglobular星团brodieglobular星团brodieglobular这是因为球状星团的形成与星系历史上的恒星形成阶段有关，而且球状星团以基本不变的明亮信标形式存在，尤其是在星系晕中。球状星团也是简单的恒星群，因此更容易分析和理解。为了充分利用球状星团的独特能力来澄清一些悬而未决的问题，包括暗物质的分布和早期星系的恒星形成历史，理论模型和观测之间必须有协同作用，特别是在低红移的地方，星系可以进行适当的详细研究。这种银河考古学的方法最近在本星系群中得到了有益的应用，现在将其扩展到几十个百万秒差距的距离，从而扩展到更有代表性的宇宙横截面是及时的。该项目将集中在两个关键领域：1)星系组装和暗物质的作用，即星系的构建块如何以及何时结合；2)恒星群，即恒星如何以及何时在这些构建块中形成？它涉及对球状星团系统的基本特性进行前所未有的系统调查，以及它们与宿主星系的关系，特别关注早期型星系。这是球状星团和星系研究在宇宙学背景下的第一次建设性整合。本调查将结合创新的观察，使用一套世界？美国最强大的地面设施，拥有世界领先的研究团队，涵盖广泛的子学科。关于附近星系化学动力学特性的里程碑式数据集将在未来几年取得丰硕的科学成果。此外，与一个名为“科学伙伴”的全国性非营利组织的伙伴关系将大大增强这项工作的影响。目前充满活力和成功的专业和公众外展计划将继续下去，并成功地将女性，本科生和少数民族纳入前沿研究。

AST-0808099BrodieGlobular star clusters are powerful probes of the formation epochs, assembly mechanisms, and subsequent evolution of galaxies. This is because of the association of globular cluster formation with star-forming episodes in a galaxy's history, and because globular clusters survive as largely unaltered bright beacons, particularly in galaxy halos. Globular clusters are also simple stellar populations, and thus more easily analyzed and understood. To exploit to its fullest the unique ability of globular clusters to clarify outstanding issues, including the distribution of dark matter and the star formation histories of early-type galaxies, there must be a synergy between theoretical models and observations, particularly at low redshift where galaxies may be studied in suitable detail. This approach of galactic archaeology has recently been gainfully applied in the Local Group, and it is timely to extend it to distances of dozens of megaparsecs, and thus to a more representative cross-section of the Universe. This project will focus on two key areas: 1) Galaxy assembly and the role of dark matter, that is, how and when do the building blocks of galaxies combine, and 2) Stellar populations, that is, how and when do stars form within these building blocks? It involves an unprecedented systematic survey of the fundamental properties of globular cluster systems, and how they relate to their host galaxies, with a particular focus on early-type galaxies. This is the first constructive integration of globular cluster and galaxy research in a cosmological context.This survey will couple innovative observations using a suite of the world?s most powerful ground-based facilities with a team of world-leading researchers spanning a wide range of sub-disciplines. The landmark dataset on the chemo-dynamical properties of nearby galaxies will be scientifically fruitful for years to come. In addition, partnership with a national, non-profit organization called Science Buddies will greatly enhance the impacts of this work. The current vigorous and successful program of professional and public outreach will continue, with a proven record of successfully including women, undergraduates, and minorities in forefront research.