A detailed mass-calibration study of intermediate and high-redshift galaxy clusters with Gravitational Lensing and X-ray techniques

通过对宇宙微波背景辐射（CMB）的研究，首次高精度地精确测定了基本宇宙学参数。超越这些大爆炸的大规模原始遗迹，我们可以测试宇宙学模型，并确定我们宇宙的基本成分，动力学和几何形状，也可以用星系团作为宇宙网络的非线性示踪剂。它们代表了我们宇宙中最大的暗物质晕，它们只是相对最近才形成的。因此，基于星系团的宇宙学研究是对CMB结果的补充，它们允许重要的一致性检查。使用星系团进行宇宙学研究有两个明显的先决条件：首先，我们需要大的，定义明确的集群样本，并对潜在的选择函数有深刻的理解。其次，我们需要能够精确地确定和校准集群样本的质量。我们的小组正在领导几个观测机会，其科学目标是对不同时期的星系团大样本进行彻底的质量分析。这个建议的重点是上面提到的第二个先决条件：集团质量的精确校准。主要目标是对五个中高红移（z = 0.3 − 0.55）星系团的样本进行精确的质量校准研究。对于所有星系团，我们都有来自ACS@HST的高质量光学天基镶嵌数据和来自地面的补充多色观测，用于引力透镜研究。独立和互补的质量估计将来自使用现有钱德拉和XMM数据的X射线研究。结合X射线和透镜研究将使我们能够深入了解这些系统的质量分布。我们的团队可以建立在我们在最明亮的X射线星系团RXJ 1347 −1145的第一个试点计划中获得的重要专业知识的基础上。

The first precise determination of the fundamental cosmological parameters with high precision has been undertaken with studies of the Cosmic Microwave Background (CMB). Going beyond those large-scale, primordial relics of the Big Bang, we can test cosmological models and determine the fundamental ingredients, the dynamics and the geometry of our Universe also with galaxy clusters as non-linear tracers of the Cosmic Web. They represent the largest dark matter haloes in our Universe and they formed only relatively recently. Therefore, cosmological studies based on galaxy clusters are complementary to CMB results and they allow important consistency checks. To use galaxy clusters for cosmological studies has two obvious prerequisites: First, we need large, well defined cluster samples with a profound understanding of the underlying selection functions. Second, we need to be able to precisely determine and to calibrate the masses of our cluster sample. Our group is leading several observational opportunities whose scientific objective is the thorough mass analysis of large samples of galaxy clusters at different epochs. This proposal focuses on the second prerequisite mentioned above: The precise calibration of cluster masses. The primary goal is to perform a precise mass calibration study on a sample of five medium-to-high redshift (z = 0.3 − 0.55) galaxy clusters. For all clusters we have high-quality optical space-based mosaic data from ACS@HST and supplementary multi-colour observations from the ground for gravitational lensing studies. Independent, and complementary mass estimates will come from X-ray studies using already existing Chandra and XMM data. The combined X-ray and lensing study will allow us to gain profound insight in the mass distribution of these systems. Our group can build on significant expertise which we gained in a first pilot program on the most luminous X-ray cluster RXJ1347−1145.