COLDz II: Ultra-Deep Imaging of the Cold Gas History of the Universe

该项目将继续最全面的计划，以测量宇宙的冷气体的历史与美国国家科学基金会的卡尔G。Jansky甚大阵列（VLA） 该项目的目标是完成整个宇宙历史中星系形成和演化的图片。冷气体是星系中恒星形成的燃料。它是理解早期以来恒星形成的关键。VLA计划的这一扩展将提供自大爆炸以来137亿年中大约11年的测量。随着十倍以上的曝光时间，它将导致前所未有的微弱星系的识别。 除了在学术期刊上发表外，该方案的研究结果还将向儿童、青年学生和普通观众公开传播。它将直接解决当前十年最优先的科学目标之一，揭示像我们的银河系及其祖先这样的星系是如何成长为今天的样子的。 该项目的重点是对美国国家科学基金会的卡尔G。Jansky甚大阵列（VLA）CO高红移亮度密度（COLDz）巡天，主要目标是系统地测量宇宙时间内分子气体的体积密度，即，大爆炸以来星系中星星形成和恒星质量积累的基本驱动力。由于我们目前的观测结果和最先进的建模工作之间的紧张关系，拟议的扩展将提供比初始测量数量级的改进。该项目将为推动未来美国旗舰设施的关键技术发展提供坚实的基础，例如ngVLA（该小组以前的研究推动了其关键科学目标之一）。与以前的工作相比，该项目将在更完整的宇宙历史覆盖范围内研究暗星系对气体密度的贡献，包括更深入地了解物理量推导的统计和系统不确定性。一系列针对幼儿、各级学生和公众（包括贫困社区）的实践教育、研究培训和外展活动将扩大该研究的影响。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

This project will continue the most comprehensive program to measure the cold gas history of the universe with the NSF's Karl G. Jansky Very Large Array (VLA). The goal of this project is to complete the picture of galaxy formation and evolution throughout cosmic history. Cold gas is the fuel for the formation of stars in galaxies. It holds the key towards understanding the buildup of stars since early epochs. This extension of the VLA program will provide measurements across approximately eleven of the 13.7 billion years since the Big Bang. With more than ten times longer exposure times, it will lead to the identification of unprecedentedly faint galaxies. In addition to being published in academic journals, the findings of this program will be publicly disseminated to children, young students, and general audiences. It will directly address one of the highest-priority science objectives of the current decade by revealing how galaxies like our Milky Way and its ancestors grew to become what they are today. This project focuses on a comprehensive analysis of the second phase of the NSF's Karl G. Jansky Very Large Array (VLA) CO Luminosity Density at High Redshift (COLDz) survey, with the principal goal to systematically measure the volume density of molecular gas through cosmic times, i.e., the fundamental driver of star formation and stellar mass buildup in galaxies since the Big Bang. Motivated by tensions between our current observations and state-of-the-art modeling efforts, the proposed expansion will provide order-of-magnitude improvements over the initial measurements. The project will provide a solid foundation for motivating key technological developments for future US-based flagship facilities, such as the ngVLA (previous research by this group motivated one of its key science goals). Compared to previous work, this project will investigate the contribution of fainter galaxies to the gas density over a more complete coverage of cosmic history, including a deeper understanding of statistical and systematic uncertainties for the derivation of physical quantities. A diverse set of hands-on education, research training, and outreach events targeting young children, students at all levels, and the public, including underprivileged communities, will broaden the impact of this research.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.