Measuring the Growth of Structure with Millimeter-Wavelength Surveys

用毫米波测量测量结构的生长

• 批准号: 1102762
• 负责人: Neelima Sehgal
• 金额: $ 8.3万
• 依托单位: Sehgal Neelima
• 依托单位国家: 美国
• 项目类别: Fellowship Award
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-10-01 至 2012-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1102762&HistoricalAwards=false
• 关键词: Measuring; Growth; Structure; Millimeter; Wavelength

Dr. Neelima Sehgal is awarded an NSF Astronomy and Astrophysics Postdoctoral Fellowship to carry out a program of research and education at Princeton University. Ground-based millimeter-wavelength surveys are underway and are detecting tens to hundreds of galaxy clusters by their Sunyaev-Zel'dovich (SZ) signal, in which high-energy electrons distort the cosmic microwave background radiation (CMB) through inverse Compton scattering, in which the low energy CMB photons receive energy boost during collision with the high energy cluster electrons. These surveys have presented their first measurements of the cluster number density evolution over cosmic time and can potentially provide precision measurements of structure growth. This, in turn, could discriminate between dark energy as a component of the Universe or as a manifestation of General Relativity's failure on the largest scales. Dr. Sehgal will build on her previous work to lead an analysis of the first cosmological constraints from an SZ-selected sample of galaxy clusters detected with the Atacama Cosmology Telescope. She will play a leading role in the determination of cosmological parameters from larger and more sensitive SZ cluster surveys and in upgrading simulations of the millimeter-wavelength sky by calibrating to the latest multi-wavelength observations. The latter will help reduce sources of systematic uncertainty in the cosmological analysis. Dr. Sehgal will also explore the feasibility of measuring cluster peculiar velocities using millimeter-wave simulations and thereby assess their utility as an alternative probe of structure growth.Dr. Sehgal will also work with the New Jersey Astronomy Center for Education to develop and support several series of class modules that teach high-school students about key concepts in cosmology. She will also train high-school teachers on the use of these modules and assess their effectiveness through surveys. These modules will be distributed to high-schools nationwide.

Neelima Sehgal博士被授予NSF天文学和天体物理学博士后奖学金，在普林斯顿大学开展研究和教育计划。地面毫米波长探测正在进行中，并正在通过其Sunyaev-Zel'dovich（SZ）信号探测数十至数百个星系团，其中高能电子通过逆康普顿散射扭曲宇宙微波背景辐射（CMB），其中低能CMB光子在与高能团簇电子碰撞期间获得能量提升。这些调查已经提出了他们的第一次测量的星系团数量密度演变在宇宙时间，并可能提供精确的测量结构的增长。这反过来又可以区分暗能量是宇宙的一个组成部分，还是广义相对论在最大尺度上失败的表现。Sehgal博士将在她以前的工作的基础上，领导对阿塔卡马宇宙学望远镜探测到的星系团的SZ选择样本的第一个宇宙学约束的分析。她将发挥主导作用，从更大和更敏感的SZ集群调查的宇宙学参数的确定，并在升级模拟毫米波长的天空校准到最新的多波长观测。后者将有助于减少宇宙学分析中系统不确定性的来源。Sehgal博士还将探索使用毫米波模拟测量星系团特有速度的可行性，从而评估它们作为结构增长的替代探测器的实用性。Sehgal博士还将与新泽西天文学教育中心合作，开发和支持几个系列的课程模块，教授高中生宇宙学的关键概念。她还将培训高中教师如何使用这些模块，并通过调查评估其有效性。这些单元将分发给全国的高中。