Polarization Observations of the Microwave Background Radiation with the Cosmic Background Imager

用宇宙背景成像仪对微波背景辐射进行偏振观测

• 批准号: 0206416
• 负责人: Anthony C. Readhead
• 金额: $ 97万
• 依托单位: California Institute of Technology
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-10-01 至 2004-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0206416&HistoricalAwards=false
• 关键词: Polarization; Observations; Microwave; Background; Radiation

AST-0206416Readhead, AnthonyThe cosmic microwave background radiation (CMBR) is expected to be polarized at a level of about 10%, owing to Thomson scattering, but as yet this polarization has not been detected. The Cosmic Background Interferometer (CBI) has been measuring the total intensity of the CMBR for the past two years, and with minor modifications to the receivers and the observing strategy, the CBI should be able to detect the polarization within a year. It should also measure the angular power spectrum of polarized fluctuations, if the predictions of currently favored cosmological models arecorrect. Polarization observations of the microwave background radiation will provide a number of important tests of cosmological models. For example many cosmological models with non-standard primordial power spectra are degenerate with standard models having different values of key cosmological parameters. It is possible to further test the predictions of the models and to break these degeneracies by measuring the polarization power spectrum and the cross-correlation between polarization and total intensity. Polarization observations should also help to reduce the uncertainties in key cosmological parameters, such as the baryon density, the matter density and the cosmological constant, and to place stringent limits on the epoch of reionization. This award will allow use of the CBI to make high sensitivity (1 MK) polarization observations of the cosmic microwave background radiation over the angular multipole range l = 300-1700.***

AST-0206416读数头，安东尼宇宙微波背景辐射（CMBR）预计将在大约10%的水平上偏振，由于汤姆逊散射，但这种偏振尚未被检测到。 在过去的两年里，宇宙背景干涉仪（CBI）一直在测量CMBR的总强度，只要对接收器和观测策略进行微小的修改，CBI应该能够在一年内检测到偏振。 如果当前流行的宇宙学模型的预测正确的话，它还应该测量偏振涨落的角功率谱。微波背景辐射的偏振观测将为宇宙学模型提供一系列重要的检验。 例如，许多具有非标准原始功率谱的宇宙学模型与具有不同关键宇宙学参数值的标准模型退化。 可以进一步测试模型的预测，并通过测量偏振功率谱和偏振与总强度之间的互相关来打破这些简并。极化观测还应有助于减少重子密度、物质密度和宇宙学常数等关键宇宙学参数的不确定性，并对再电离的时间加以严格限制。该合同将允许使用CBI对l = 300-1700的多极角范围内的宇宙微波背景辐射进行高灵敏度（1 MK）偏振观测。