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: 1313287
• 负责人: John Kovac
• 金额: $ 40.01万
• 依托单位: Harvard University
• 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=1313287&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，整个可观测宇宙是在亚核体积的戏剧性超光速“膨胀”中产生的。物质的剧烈加速会产生宇宙引力波背景（CGB），其幅度可以衡量暴胀的能量规模。 CGB 在宇宙微波背景 (CMB) 的偏振中留下了微弱的特征，其幅度由张量与标量模式的比率参数化，r = T/S。许多暴胀慢滚模型产生 r ~ 0.01?0.1，对应于角度尺度上 30?100 nK rms 的峰值 CMB 波动。 检测 CGB 的偏振特征可以说是当今宇宙学中最重要的目标。 Astro2010 十年调查将寻找 CGB 描述为“最令人兴奋的探索”，并强调“旨在检测 CMB（B 模式）极化的系统需要中期投资”。 2005 年，CMB 研究工作组将此确定为该领域的最高优先事项，并确定了 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）运行，不懈地绘制银河系前景中独特的低空 800 度的天空区域 - 所谓的南洞。 150 GHz 的综合灵敏度（现在高于普朗克航天器）集中在南洞，显着提高了探测 CGB 的能力。该奖项将在三年内支持使用名为 BICEP3 的新型 CMB 旋光仪进行科学观察和分析，这是第三代紧凑型折射仪，将代表每个接收器灵敏度的另一项突破。与单个 BICEP2/SPUD 接收器相比，BICEP3 的光吞吐量进一步增加了十倍。经过三年的观测，BICEP3 在 95 GHz 下填充了 2560 个 TES，将生成当前或计划中的任何实验中最灵敏的 95 GHz 度数尺度 CMB 偏振图。 BICEP3 观测结果与 SPUD 的 150 GHz 和 220 GHz 深度覆盖相结合，将在 CMB 偏振和银河系前景之间提供更强大的区分能力。 CGB 的发现对于暴胀来说就像 CMB 的发现对于大爆炸一样。事实上，它的影响可能更广泛，因为通货膨胀直接影响到基础物理学的当前前沿。该项目将继续为在这方面拥有杰出记录的实验室的本科生和研究生以及博士后研究员（包括来自代表性不足群体的博士后）提供优秀的培训。宇宙学和南极洲的研究都激发了公众的想象力，使这种结合成为激发科学兴趣的非常有效的工具。