Studying the Evolution of Cosmic Structure with Distant X-ray selected Clusters of Galaxies

星系团是宇宙大尺度结构及其生长速率随时间变化的理想示踪剂。这使它们成为检验宇宙模型的首要探测器。它们还形成了重要的实验室，以跟踪星系和星系间重子介质作为环境条件的演化。它们为我们提供了星系和恒星形成历史的信息，以及它们通过重元素污染和熵产生对星系间介质的影响。尽管对现今星系团的数量有了很好的了解，但我们对遥远星系团的了解及其性质的宇宙学含义仍然很少。x射线观测是目前寻找大质量遥远星系团的最好方法，因为它们能以高对比度显示星系团。由XMM-Newton进行的x射线观测档案的不断增长，为进行遥远星团的调查提供了最好的可用资源，大大取代了迄今为止所有类似的努力。我们的调查项目利用这个独特的机会在z >上发现了至少30个新的星团，现在已经充分发展了它的实力，已经发现了5个接近红移单位的星团z > 1和5，更多的光谱数据正在传输中，并且从我们广泛的xmm -牛顿档案搜索和光度跟踪计划中获得了更多的候选星团。这些发现为我们提供了有趣的研究案例，提供了第一次有趣的见解，并导致了第一次出版物。要达到该项目的全部目标，仍需要进行大量的工作和后续观察，其中很大一部分将在下一个筹资期内实现。我们将能够解决下面列出的所有要点。该项目的最终科学目标是：(1)描述大尺度结构演化，约束宇宙学模型参数；(2)获得星系团内部和结构特性演化的统计描述，特别是关于可观测到的星系团质量关系演化的信息；(3)为星系团星系种群和星系团内等离子体的演化特征提供基础。第一批研究已经证实，在红移1.4左右仍然存在明显的古老红星系序列，并且在z = 0.97处获得了星系团星系的严格年龄约束。根据计划和计划的后续观测，我们现在可以相当安全地预测至少有15个星团在z >.1，甚至更接近这个极限。这将使我们能够对这些高红移星团的x射线光度函数的演变设定严格的限制，并允许在项目完成之前进行第一次宇宙学测试。对暗能量本质的重大限制将来自大约10个这样的星团的统计子样本，通过更深的x射线观测，可以测量温度和气体质量，正如我们已经从三个探测中获得的那样。这取决于对这些星团进行深x射线观测的建议是否已经成功。这些数据也可以很好地概述ICM高红移重元素富集的历史。随着正在进行的覆盖约40-50平方度的调查的完成（将在本资助期结束后不久完成），我们将有一个独特而强大的样本量，以获得有关比例关系和宇宙模型测试的有用统计数据。这个项目将作为一个非常重要的探路者，为即将到来的使用Sunyaev-Zeldovich效应和随后的eROSITA对遥远星团进行的大规模调查提供帮助。

Galaxy clusters are ideal tracers of the cosmic large-scale structure and its growth rate as a function of time. This makes them prime probes for the test of cosmological models. They also form important laboratories to follow the evolution of galaxies and the baryonic intergalactic medium as a function of environmental conditions. They provide us with information on galaxy and star formation history and their effects on the intergalactic medium through heavy element pollution and entropy production. Whereas a good understanding of the present day cluster population is emerging, our knowledge of distant clusters and the cosmological implications of their properties is still sparse. X-ray observations are currently the best means to find massive distant galaxy clusters, because they display the clusters at high contrast.The growing archive of X-ray observations conducted with XMM-Newton provides the best available resource to conduct a survey for distant clusters, vastly superseding all similar efforts to date. Our survey project that exploits this unique opportunity to find at least 30 new clusters at z > 1 has now developed its full strength with the detection of already 5 clusters z > 1 and 5 close to redshift unity, more spectroscopic data in the pipeline and a reservoir of further candidates from our extensive XMM-Newton archive search and phomoteric follow-up program. These discoveries have supplied us with interesting study cases, provided first interesting insights and led to first publications. A large amount of work and follow-up observations are still required to reach the full goal of the project, a substantial part of which will be achieved within the coming funding period. We will be able to already address all the important points listed below.The final scientific goals of the project are (i) to characterize the large-scale structure evolution, to constrain cosmological model parameters, (ii) to obtain a statistical description of the evolution of the internal and structural properties of clusters, in particular information on the evolution of the observable-cluster mass relation, and (iii) to provide the basis for the evolutionary characterization of the cluster galaxy population and the intracluster plasma. The first studies have already confirmed that a pronounced sequence of old red galaxies still exists at redshifts around 1.4, and tight age constraints of cluster galaxies have been obtained for a System at z = 0.97. With the scheduled and planned follow-up observations we can now quite safely predict to get at least 15 clusters at z > 1 and more close to this limit. This will enable us to set tight constraints on the evolution of the X-ray luminosity function of clusters at these high redshifts and allow first approaches to cosmological tests before the completion of the project. Significant constraints on the nature of Dark Energy would come from a statistical subsample of about 10 of these clusters with deeper X-ray observations allowing a temperature and gas mass measurment, as already obtained for three of our detections. This depends on a ready success of proposals of deep X-ray observations for these clusters. Such data would also provide a very good overview on the history of heavy element enrichment of the ICM at high redshift.With the completion of the survey in progress covering about 40-50 square degrees (which will come shortly after the end of this funding period) we will have a unique and powerful sample size to get useful statistics on the scaling relations and on cosmological model tests. This project will act as a very important pathfinder for the upcoming large surveys of distant clusters using the Sunyaev-Zeldovich effect and later with eROSITA.