Extragalactic Astrophysics and Cosmic-Ray Physics with HAWC

伽马射线是电磁辐射的最高能量形式。对天体物理伽马射线的观测可以作为宇宙中最极端环境中的物理条件和过程的探测器，并可用于测试基本物理。高海拔水切伦科夫天文台(HAWC)位于墨西哥内格拉山脉的山坡上，是一个地面设施，具有独特的观测高能伽马射线的能力。HAWC还能够观测宇宙射线，这是一种高能量的亚原子粒子，以接近光速的速度运行。宇宙射线的起源和加速机制尚不清楚。最高能量的宇宙射线可能起源于我们银河系外的极端天体物理现象。该奖项支持威斯康星大学的科学家分析用HAWC收集的伽马射线和宇宙射线数据。他们将研究来自河外伽马射线源的耀斑，并测量宇宙射线到达方向的各向异性。该组织将与“El University so es Tuyo”项目合作，为当地讲西班牙语的学生提供外展和教育项目。凭借其大的瞬时视场和连续的操作，HAWC每天测量三分之二的天空。威斯康星大学的研究小组将研究河外伽马射线源中的耀斑活动，并测量从TeV到PeV能量范围内的宇宙线各向异性。该小组开发并实施了一个耀斑监测程序，该程序可以实时分析HAWC数据，以搜索耀斑活动。发出快速警报，以触发其他望远镜在其他波长或观测宇宙线或中微子的设施进行搜索。该小组将继续运作并进一步开发耀斑监视器，他们将分析在耀斑事件期间获取的数据。该小组将使用新的方法，将HAWC的天空地图与南极冰立方中微子天文台的地图结合起来，研究南北半球的宇宙线各向异性，以解决观测到的偶极强度和预期的偶极强度之间的长期差异。

Gamma-rays are the highest energy form of electromagnetic radiation. Observations of astrophysical gamma-rays serve as probes of physical conditions and processes in the most extreme environments throughout the Universe, and can be used to test fundamental physics. The High Altitude Water Cherenkov (HAWC) observatory, located on the slopes of the Sierra Negra in Mexico, is a ground-based facility designed with unique capabilities to observe very high energy gamma-rays. HAWC is also capable of observing cosmic-rays, which are highly energetic sub-atomic particles that travel near the speed of light. The origin and acceleration mechanisms of cosmic rays are unknown. The highest energy cosmic rays likely originate in extreme astrophysical phenomena outside our galaxy. This award supports scientists at the University of Wisconsin in the analysis of gamma-ray and cosmic-ray data collected with HAWC. They will study flares from extragalactic gamma-ray sources and measure the anisotropy in the arrival directions of cosmic rays. The group will partner with the "El Universo es Tuyo" program in outreach and education programs for local Spanish-speaking students. With its large instantaneous field of view and continuous operations HAWC surveys two-thirds of the sky every day. The University of Wisconsin group will study flaring activity in extragalactic gamma-ray sources and measure the cosmic-ray anisotropy in the TeV to PeV energy range. The group has developed and implemented a flare monitor program that analyzes HAWC data in real-time to search for flaring activity. Rapid alerts are sent out to trigger searches by other telescopes at other wavelengths or facilities that observe cosmic rays or neutrinos. The group will continue to operate and further develop the flare monitor, and they will analyze the data taken during flaring events. Using new methods and combining HAWC skymaps with maps from the IceCube neutrino observatory at the South Pole, the group will study cosmic-ray anisotropy across the northern and southern hemispheres to address the long-standing discrepancy in the observed and expected dipole strength.