Cosmography with Cluster Strong Lensing

星团强透镜宇宙学

• 批准号: 1009444
• 负责人: Priyamvada Natarajan
• 金额: $ 36.78万
• 依托单位: Yale University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-09-15 至 2015-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1009444&HistoricalAwards=false
• 关键词: Cosmography; Cluster; Strong; Lensing

This project will apply a novel technique in gravitational lensing to the measurement of fundamental parameters related to dark energy and the acceleration of the cosmic expansion. The focus is on strong gravitational lensing by massive clusters of galaxies. In strong lensing, the gravitational bending of light by the cluster produces multiple images of background galaxies. The new aspect to be explored in this project concerns those cases where there are multiple images of multiple sources at different distances behind the cluster. Because the lens is the same, analysis of the images can permit the extraction of the lens-source geometry, from which follow constraints on the overall cosmology. Applying this technique quantitatively requires good models for the mass distributions in galaxy clusters and along the full line of sight. To this end, the Principal Investigator and a supported graduate student will perform a ray-tracing analysis through cosmological structure-formation simulations, to quantify the expected statistical and systematic errors on the recovery of cosmological parameters from simulated lens systems. They will then apply the analysis to a sample of five cluster lenses, for which Hubble Space Telescope imaging data exist, and obtain joint constraints on the cosmological matter density and the dark-energy equation of state. In addition to advising the student supported by this project, the Principal Investigator will develop and teach a seminar in scientific communication for undergraduate astronomy majors. This course will jointly benefit university and K-12 students though the presentations that enrolled students will make to a high-school physics class.

该项目将应用引力透镜中的一种新技术来测量与暗能量和宇宙膨胀加速有关的基本参数。重点是大质量星系团的强引力透镜效应。在强透镜中，星系团对光线的引力弯曲产生了背景星系的多重图像。在这个项目中要探索的新方面涉及的情况下，有多个图像的多个来源在不同的距离后面的集群。因为透镜是相同的，图像的分析可以允许提取的透镜源的几何形状，从下面的约束的整体宇宙学。定量地应用这种技术需要星系团和沿着整个视线的质量分布的良好模型。为此，首席研究员和一名受资助的研究生将通过宇宙学结构形成模拟进行射线追踪分析，以量化从模拟透镜系统恢复宇宙学参数的预期统计和系统误差。然后，他们将分析应用于哈勃太空望远镜成像数据存在的五个集群透镜的样本，并获得宇宙物质密度和暗能量状态方程的联合约束。除了为该项目支持的学生提供建议外，首席研究员还将为本科天文学专业的学生开发和教授科学交流研讨会。本课程将共同受益于大学和K-12学生，尽管入学学生将在高中物理课上做演讲。