Study of the Highest Energy Cosmic Rays with the Pierre Auger Observatory

超高能宇宙射线（uhecr）的测量提供了前所未有的宇宙视野，并提供了超越地面加速器所能获得的能量的天体物理学。皮埃尔·奥格天文台（PAO）是南半球最大的宇宙射线探测器阵列，它的观测提高了我们对UHECR源的理解，包括粒子如何在极端环境中加速。该奖项支持科罗拉多矿业学院（Mines）和凯斯西储大学（CWRU）的研究人员通过对PAO仪器的重大贡献继续研究最高能量粒子。这些项目将利用创新技术来研究PAO探测器和大气系统的不确定性，使天空中UHECR源的细微表现与观测到的主要粒子质量和电荷相结合成为可能。该小组还将继续研究通过微阵列探测器Auger@TA在北半球观测到的PAO和望远镜阵列天文台之间的宇宙射线能量尺度和通量差异。该项目包括为研究生和本科生提供实验方法方面的研究培训，包括在大气科学和商业GPS授时方面的潜在更广泛应用。目前PAO测量的能谱、各向异性、主要成分、中微子和光子极限以及质子-空气横截面为研究高能宇宙提供了独特的途径。大气对PAO荧光探测器绝对和相对能量尺度的影响仍然是天文台科学的一个重要组成部分，由该团队管理的测试光束激光设备是现有阵列和正在进行的升级的核心。同时，Auger@TA微阵列目前正在调试中，计划进行为期两年的科学运行，将提供同时和独立的广泛的空气淋浴事件数据，以交叉校准PAO和TA探测器。这样做将允许第一次直接比较实验的宇宙射线能量尺度，以确定观测到的能量尺度和通量差异的起源。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。

Measurements of ultra-high-energy cosmic rays (UHECRs) have provided an unprecedented view of the universe and access to astro-physics at energies beyond those accessible at terrestrial accelerators. Observations performed with the Pierre Auger Observatory (PAO), the largest cosmic ray detector array in the southern hemisphere, have advanced our understanding of UHECR sources, including how the particles are accelerated in the extreme environments. This award supports researchers at the Colorado School of Mines (Mines) and Case Western Reserve University (CWRU) to continue studies of the highest energy particles via major contributions to PAO instruments. The awarded activities will leverage innovative techniques to study the PAO detector and atmospheric systematic uncertainties, making it possible to couple the subtle manifestations of UHECR sources in the sky with the observed primary particle mass and charge. The team will also continue the investigations of cosmic ray energy-scale and flux discrepancies observed between PAO and the Telescope Array Observatory in the northern hemisphere via the micro-array detecter Auger@TA. The program includes research training in experimental methods for graduate and undergraduate students, including potential broader applications for atmospheric science and commercial GPS timing.The current PAO measurements of energy spectra, anisotropy, primary composition, neutrino and photon limits, and proton-air cross-section provide unique access to the high-energy universe. The influence of the atmosphere on the PAO fluorescence detector absolute and relative energy-scales remains a crucial element of science of the observatory, and the test-beam laser facilities managed by the team are central to the existing array and the on-going upgrade, AugerPrime. In parallel, the Auger@TA micro-array is currently under commissioning, with a planned two-year science run that will provide simultaneous and independent extensive air shower event data to cross-calibrate PAO and TA detectors. Doing so will permit a first direct comparison of the cosmic-ray energy-scales of the experiments to determine the origin of the observed energy-scale and flux discrepancies.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.