CAREER: WoU-MMA: Understanding the Neutrino Sky

宇宙射线，即从遥远的源头到达地球的粒子，其能量可能超过最高能量的人造粒子加速器的1000万倍。然而，在它们被发现一个世纪之后，这些引人注目的粒子的起源，以及赋予它们这些能量的过程仍然未知。在过去的十年里，南极的冰立方中微子观测站第一次看到了这些源，揭示了其中一些源的大致位置，但没有精确地确定它们是什么。该奖项支持分析现有冰立方数据的新方法，以解开这个谜团，以及开发下一代天文台P-ONE的第一步，P-ONE位于华盛顿海岸外的太平洋底部，将提供更高精度的测量，并完全打开冰立方提供的宇宙新窗口，以及为研究深海提供独特的平台。作为这一努力的一部分，该奖项还将支持改善物理学教学的工作，以提高可及性，强调这门学科是一门实验科学，而不仅仅是一门数学练习，并更好地将课程与学术和工业职业所需的技能结合起来。中微子能够穿过光线不透明的障碍物，为高能量和遥远的宇宙提供了独特的视角。在过去的八年里，冰立方中微子天文台首次观测到来自天体物理物体的高能中微子，首次探测到明亮的漫射背景（2014年）和第一个来源（2018年）。这些结果提出了一些令人困惑的问题：中微子天空比任何波长的光都更具有各向同性，除了宇宙微波背景，而且第一个（可能也是最亮的）来源离地球很远，其他地方也不引人注目。总之，这些观测结果有力地表明，中微子正在告诉我们一些关于宇宙的根本性的新东西，一些我们没有预料到的东西，也没有其他方法可以看到，但我们确实有数据来理解它可能是什么。这个奖项通过两条途径来解决这个问题：分析冰立方现有数据的新方法，特别是通过与活动星系的毫米波段观测相互关联，其中已经报道了一些线索；以及为东北太平洋的新中微子望远镜P-ONE开发电子设备。预计P-ONE的角度分辨率将比冰立方高4-5倍，预计探测到的中微子源数量将增加一个数量级，并允许首次对中微子源进行群体研究。此外，P-ONE的峰值灵敏度将在南部天空，不像冰立方，这使得它与我们银河系的研究和大多数下一代电磁天文台（Rubin， ELT, CMB-S4， SKA， SWGO等）的视场非常匹配。该奖项的预期教育和推广方面包括在密歇根学校的推广，增加本科生到研究生过渡的多样性的两个项目，以及在研究生和本科生水平上教授实验物理的新项目。此外，该奖项还支持在印象五号科学中心（Impression Five science center）设立一个关于宇宙射线和粒子物理学的新展览。印象五号科学中心是密歇根州中部的一个主要科学教育中心，每年吸引近20万游客。该奖项与美国国家科学基金会的“宇宙之窗：多信使天体物理学时代”的大构想相一致，因为它协调了利用长波（毫米/厘米）光子与来自冰立方的高能中微子的多信使观测的使用，并将通过提高对漫射源的理解来改善数据的解释。该奖项反映了美国国家科学基金会的法定使命，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。

Cosmic rays, particles arriving at the Earth from distant sources, can have energies exceeding 10 million times that of the highest-energy man-made particle accelerators. A century after their discovery, however, the origin of these remarkable particles, and the process responsible for giving them these energies remains unknown. A first glimpse at these sources has come over the last decade from the Antarctic's IceCube Neutrino Observatory, revealing the approximate locations of a number of them, but without the precision to identify what they are. This award supports new approaches to analyze existing IceCube data to untangle this mystery as well as the first steps to develop a next-generation observatory, P-ONE, at the bottom of the Pacific Ocean off the Washington coast that will provide much higher-precision measurements and fully open the new window on the universe provided by IceCube -- as well as providing a unique platform for studying the deep ocean. As part of this effort, the award will also support work to improve teaching in physics to improve accessibility and emphasize the subject as an experimental science rather than as only a mathematical exercise and to better align coursework with the skills needed for both academic and industry careers.Neutrinos, able to pass through obstacles opaque to light, provide a unique view of the high-energy and distant universe. Over the last eight years, the IceCube Neutrino Observatory has provided the first glimpse of these high-energy neutrinos from astrophysical objects, with the first detection of a bright, diffuse background (2014) and of the first source (2018). These results present something of a puzzle: The neutrino sky is more isotropic than light at any wavelength except the cosmic microwave background and the first (and presumably brightest) source is both a vast distance from Earth and otherwise unremarkable. Together, these observations strongly suggest that neutrinos are telling us something fundamentally new about the universe, something that we have not anticipated and have no other way to see, but we do yet have the data to understand what it might be. This award approaches this problem on two paths: new methods for analysis of existing IceCube data, notably by cross-correlation with millimeter-band observations of active galaxies, of which hints have been reported, and by development of the electronics for a new neutrino telescope in the northeast Pacific, P-ONE. P-ONE is expected to achieve angular resolution 4-5 times better than IceCube, increasing the expected number of detected sources by an order of magnitude and allowing the first population studies of neutrino sources. Moreover, P-ONE's peak sensitivity will be in the southern sky, unlike IceCube, which makes it well-matched to studies of our galaxy and the fields of view of most next-generation electromagnetic observatories (Rubin, ELT, CMB-S4, SKA, SWGO, etc.). Anticipated education and outreach aspects of the award include outreach in Michigan schools, a pair of programs to increase diversity at the undergraduate to graduate transition, and new programs for teaching experimental physics at the graduate and undergraduate level. In addition, the award supports the installation of a new exhibit on cosmic rays and particle physics at the Impression Five science center, a major center for science education in mid-Michigan attracting nearly 200,000 visitors a year.The award is aligned with the NSF Big Idea of Windows on the Universe: the Era of Multi-messenger Astrophysics as it coordinates the use of multi-messengers observations utilizing long wavelength (mm/cm) photons with high energy neutrinos from IceCube and will improve the interpretation of data especially through improving the understanding of diffuse sources.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.