Collaborative Research: Science Observation with BICEP3 CMB Polarization Experiment

合作研究：利用 BICEP3 CMB 极化实验进行科学观察

• 批准号: 1313062
• 负责人: James Bock
• 金额: $ 35.59万
• 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: 2013
• 资助国家: 美国
• 起止时间: 2013-08-15 至 2017-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1313062&HistoricalAwards=false
• 关键词: Collaborative; Research; Science; Observation; BICEP3

Evidence is mounting that the entire observable Universe was spawned in a dramatic superluminal "Inflation" of a sub-nuclear volume. This violent acceleration of matter would have produced a cosmic gravitational-wave background (CGB), the amplitude of which measures the energy scale of Inflation. The CGB imprints a faint signature in the polarization of the Cosmic Microwave Background (CMB) with an amplitude parameterized by the ratio of tensor to scalar modes, r = T/S. Many slow-roll models of Inflation produce r ~ 0.01?0.1, corresponding to peak CMB fluctuations of 30?100 nK rms on degree angular scales. Detecting the polarization signature of the CGB is arguably the most important goal in cosmology today. The Astro2010 Decadal Survey described the search for the CGB as "the most exciting quest of all", and emphasized that "mid-term investment is needed for systems aimed at detecting the (B-mode) polarization of the CMB". In 2005, the Task Force on CMB Research identified this as the highest priority for the field and established a target sensitivity of r = 0.02. The ongoing BICEP/BICEP2/SPUD series of experiments is dedicated to this science goal. They began operating at the South Pole Station (Antarctica) in 2006 and are relentlessly mapping an 800-deg2 region of the sky that uniquely low in Galactic foregrounds - the so-called Southern Hole. The combined sensitivity at 150 GHz (now greater than that of the Planck spacecraft) is concentrated on the Southern Hole increasing the ability to detect the CGB significantly. This award will support for three years the science observations and analysis with a new CMB polarimeter called BICEP3 - a third-generation compact refractor that will represent another breakthrough in per-receiver sensitivity. BICEP3 provides a further ten-fold increase in optical throughput compared to a single BICEP2/SPUD receiver. Populated with 2560 TESs at 95 GHz over three years of observing, BICEP3 will produce the most sensitive degree-scale CMB polarization maps of 95 GHz of any current or planned experiment. BICEP3 observations, when combined with SPUD's deep 150 GHz and 220 GHz coverage, will provide significantly more powerful discrimination between CMB polarization and Galactic foregrounds. Detection of the CGB would be to Inflation what the discovery of the CMB was to the Big Bang. Indeed its impact might be even broader, as Inflation directly bears on the current frontiers of fundamental physics. The project will continue to provide excellent training for undergraduate and graduate students, as well as postdoctoral fellows (including those from underrepresented groups) in laboratories that have exceptional track records in this regard. Cosmology and research in Antarctica both capture the public imagination, making this combination a remarkably effective vehicle for stimulating interest in science.

越来越多的证据表明，整个可观测宇宙都是在亚核体积的超光速“膨胀”中产生的。这种物质的剧烈加速会产生宇宙引力波背景波（CGB），其振幅可以衡量暴胀的能量尺度。CGB在宇宙微波背景（CMB）的偏振中留下了微弱的信号，其振幅由张量模式与标量模式之比r = T/S参数化。许多暴胀慢滚模型产生r ~ 0.01 ~ 0.1，对应于CMB波动的峰值为30？100 nK均方根在度角尺度上。探测CGB的偏振特征可以说是当今宇宙学中最重要的目标。Astro2010年十年调查将对CGB的搜索描述为“最令人兴奋的探索”，并强调“需要对旨在探测CMB （b模）极化的系统进行中期投资”。2005年，宇宙微波背景研究工作组（Task Force on CMB Research）将其确定为该领域的最高优先级，并建立了r = 0.02的目标灵敏度。正在进行的BICEP/BICEP2/SPUD系列实验致力于实现这一科学目标。他们于2006年开始在南极站（南极洲）工作，并坚持不懈地绘制天空中一个800度2的区域，这个区域在银河系前景中非常低，被称为“南洞”。150千兆赫的综合灵敏度（现在比普朗克航天器的灵敏度更高）集中在南洞，大大增加了探测CGB的能力。该奖项将支持为期三年的科学观测和分析，使用名为BICEP3的新型CMB偏振计，这是第三代紧凑型折射器，将代表每接收器灵敏度的另一个突破。与单个BICEP2/SPUD接收器相比，BICEP3提供了10倍的光吞吐量。在三年的观测中，BICEP3将配备2560台频率为95千兆赫的TESs，在目前或计划中的任何实验中，BICEP3将产生最灵敏的95千兆赫度的微波背景偏振图。BICEP3的观测，当与SPUD的150 GHz和220 GHz深度覆盖相结合时，将提供更强大的CMB极化和银河系前景之间的区分。CGB的探测对于暴胀的意义就像CMB的发现对于大爆炸的意义一样。事实上，它的影响可能更为广泛，因为暴胀理论直接影响到基础物理学的前沿。该项目将继续为本科生和研究生以及博士后（包括来自代表性不足群体的博士后）提供优秀的培训，这些实验室在这方面有特殊的记录。宇宙学和南极洲的研究都吸引了公众的想象力，使这一组合成为激发科学兴趣的非常有效的工具。