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: 1313010
• 负责人: Chao-Lin Kuo
• 金额: $ 32.6万
• 依托单位: Stanford 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=1313010&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“暴胀”中产生的。物质的这种剧烈加速会产生宇宙引力波背景（CGB），其振幅衡量了暴胀的能量尺度。CGB在宇宙微波背景（CMB）的偏振中留下了一个微弱的签名，其振幅由张量模式与标量模式之比r = T/S参数化。许多慢卷模型的通货膨胀产生r ~ 0.01？0.1，对应于峰值CMB波动30？角度刻度上为100 nK rms。 探测CGB的偏振特征可以说是当今宇宙学中最重要的目标。Astro 2010年十年调查将寻找CGB描述为“最令人兴奋的探索”，并强调“需要对旨在探测CMB（B模式）极化的系统进行中期投资”。2005年，CMB研究工作队将其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/BICEP 2/SPUD系列实验致力于这一科学目标。他们于2006年开始在南极站（南极洲）工作，并坚持不懈地绘制了一个800度2的天空区域，该区域在银河系前景中非常低-所谓的南洞。在150 GHz（现在大于普朗克航天器）的综合灵敏度集中在南洞，大大提高了探测CGB的能力。该奖项将支持三年的科学观测和分析与一个新的CMB偏振计称为BICEP 3-第三代紧凑型折射，这将代表每接收器灵敏度的另一个突破。与单个BICEP 2/SPUD接收器相比，BICEP 3的光吞吐量进一步增加了10倍。在三年的观测中，BICEP 3将在95 GHz处拥有2560个TES，它将产生任何当前或计划中的实验中最敏感的95 GHz度尺度CMB偏振图。BICEP 3的观测，当与SPUD的深150 GHz和220 GHz的覆盖范围相结合时，将提供更强大的区分CMB极化和银河系前景。发现CGB之于暴胀，就像发现CMB之于大爆炸。事实上，它的影响可能更广泛，因为暴胀直接关系到基础物理学的当前前沿。该项目将继续为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研究员）提供出色的培训，培训地点是在这方面有着出色记录的实验室。南极洲的宇宙学和研究都抓住了公众的想象力，使这种结合成为激发科学兴趣的非常有效的工具。