Large Angular Scale Polarization Survey of the Cosmic Microwave Background

宇宙微波背景的大角尺度偏振测量

• 批准号: 1636634
• 负责人: Charles Bennett
• 金额: $ 443.3万
• 依托单位: Johns Hopkins University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-09-15 至 2022-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1636634&HistoricalAwards=false
• 关键词: Large; Angular; Scale; Polarization; Survey

This award will fund commissioning and operations of the Cosmology Large Angular Scale Surveyor (CLASS) cosmic microwave background (CMB) polarization experiment located in the Atacama Desert in Chile. The first of two planned telescopes was recently deployed. The main science goal is to detect a polarization signal originating in a theorized rapid inflation of the universe during the first moments of the Big Bang. Broader impacts of the work include training of undergraduate students, graduate students, and postdocs. The project also has an integrated program of public outreach to engage the Baltimore public through the annual Johns Hopkins University Physics Fair, the well-established Quarknet program that trains high school teachers, and interactive planetarium shows at Baltimore city schools with large populations of under-represented minorities.Ultimately, two telescopes will make observations at frequencies of 40, 90, 150, and 220 GHz. A novel aspect of the CLASS instrumentation is that its first optical element is a variable polarization modulator (wire grid with variable offset from a flat mirror). The main science goal is to search for the inflationary gravitational wave B-mode polarization signal on angular scales of roughly 10 degrees, associated with the reionization 'bump' in the CMB angular power spectrum. Another science goal is to improve the electron-scattering optical depth of the reionization era to CMB photons by measuring the E-modes associated with the reionization signal. Development of the telescopes and other instrumentation to conduct the survey has been supported via two previous awards from NSF's Major Research Instrumentation program.

该奖项将资助位于智利阿塔卡马沙漠的宇宙学大角尺度探测器（CLASS）宇宙微波背景（CMB）极化实验的调试和运营。两个计划中的望远镜中的第一个最近已经部署。主要的科学目标是探测一个偏振信号，该信号起源于大爆炸最初时刻宇宙理论上的快速膨胀。这项工作的更广泛影响包括对本科生、研究生和博士后的培训。 该项目还有一个综合性的公众推广计划，通过每年的约翰霍普金斯大学物理博览会，培训高中教师的Quarknet计划，以及在巴尔的摩城市学校的互动天文馆展览，吸引巴尔的摩公众参与，这些学校有大量未被充分代表的少数民族。最终，两台望远镜将在40，90，150和220 GHz的频率进行观测。 CLASS仪器的一个新方面是它的第一个光学元件是可变偏振调制器（从平面镜可变偏移的线栅）。 主要的科学目标是在大约10度的角尺度上寻找暴胀引力波B模式偏振信号，与CMB角功率谱中的再电离“碰撞”有关。另一个科学目标是通过测量与再电离信号相关的E模式来改善再电离时代对CMB光子的电子散射光学深度。 望远镜和其他仪器的发展进行调查已经通过两个以前的奖项从NSF的主要研究仪器计划的支持。

项目成果

Design and characterization of new 90 GHz detectors for the Cosmology Large Angular Scale Surveyor (CLASS)

• DOI: 10.1117/12.2630081
• 发表时间: 2022-08
• 作者: C. Núñez;J. Appel;S. M. Bruno;R. Datta;Aamir Ali;C. Bennett;S. Dahal;Jullianna Denes Couto;K. Denis;J. Eimer;Francisco Espinoza;T. Essinger-Hileman;K. Helson;J. Iuliano;T. Marriage;Carolina Morales Peréz;Deniz Augusto Nunes Valle;M. Petroff;K. Rostem;Rui Shi;D. Watts;Edward J. Wollack;Zhilei Xu

Four-year Cosmology Large Angular Scale Surveyor (CLASS) Observations: On-sky Receiver Performance at 40, 90, 150, and 220 GHz Frequency Bands

四年宇宙学大角尺度测量仪 (CLASS) 观测：40、90、150 和 220 GHz 频段的空中接收器性能

• DOI: 10.3847/1538-4357/ac397c
• 发表时间: 2022
• 期刊: The Astrophysical Journal
• 作者: Dahal, Sumit;Appel, John W.;Datta, Rahul;Brewer, Michael K.;Ali, Aamir;Bennett, Charles L.;Bustos, Ricardo;Chan, Manwei;Chuss, David T.;Cleary, Joseph
• 通讯作者: Cleary, Joseph

Cosmology Large Angular Scale Surveyor (CLASS): pointing stability and beam measurements at 90, 150, and 220 GHz

宇宙学大角尺度测量仪 (CLASS)：90、150 和 220 GHz 的指向稳定性和波束测量

• DOI: 10.1117/12.2630649
• 发表时间: 2022
• 期刊: and Far-Infrared Detectors and Instrumentation for Astronomy XI
• 作者: Datta, Rahul;Brewer, Michael K.;Denes Couto, Jullianna D.;Eimer, Joseph R.;Li, Yunyang;Xu, Zhilei;Appel, John W.;Bustos, Ricardo;Chuss, David;Cleary, Joseph
• 通讯作者: Cleary, Joseph

Long-timescale stability in CMB observations at multiple frequencies using front-end polarization modulation

使用前端偏振调制在多个频率下实现 CMB 观测的长时标稳定性

• DOI: 10.1117/12.2629723
• 发表时间: 2022
• 期刊: and Far-Infrared Detectors and Instrumentation for Astronomy XI
• 作者: Cleary, Joseph;Datta, Rahul;Appel, John;Bennet, Charles;Chuss, David;Denes Couto, Julliana;Dahal, Sumit;Espinoza, Francisco;Essinger-Hileman, Thomas;Harrington, Kathleen
• 通讯作者: Harrington, Kathleen

A Projected Estimate of the Reionization Optical Depth Using the CLASS Experiment’s Sample Variance Limited E-mode Measurement

使用 CLASS 实验样本方差有限 E 模式测量对再电离光学深度进行预测估计

• DOI: 10.3847/1538-4357/aad283
• 发表时间: 2018
• 期刊: The Astrophysical Journal
• 作者: Watts, Duncan J.;Wang, Bingjie;Ali, Aamir;Appel, John W.;Bennett, Charles L.;Chuss, David T.;Dahal, Sumit;Eimer, Joseph R.;Essinger-Hileman, Thomas;Harrington, Kathleen
• 通讯作者: Harrington, Kathleen