Construction of the HAWC Gamma-Ray Observatory

该合同将为在墨西哥Sierra Negra建造的高海拔水切伦科夫（HAWC）伽马射线天文台提供资金。这里提供了建造HAWC的硬件、工程和合同（非科学家）劳动力的成本。HAWC的观测将探测宇宙中最极端的环境，为银河系内外的非热过程提供独特的视角。HAWC的主要科学目标是：(a)测量最高能量的银河系源的光谱；(b)绘制从1 TeV到100 TeV的银河系漫射伽马射线发射图，测量整个银河系的宇宙射线通量和光谱；(c)研究活动星系核的瞬态辐射；(d)监测天空中伽马射线暴产生的100 GeV辐射；(e)利用HAWC的无偏巡天寻找新的TeV物理。HAWC测量有可能揭示自然界的基本对称性，包括寻找极端能量下的洛伦兹违反，寻找宇宙中的暗物质，以及直接探测大质量遗留粒子。HAWC是一个由250个大型水箱组成的阵列，每个水箱底部安装有三个光电倍增管（pmt）。这些储罐将占地约20,000平方米。探测范围的扩大、探测高度的增加和探测器元件的光学隔离使得Milagro的灵敏度比Milagro提高了15倍，Milagro是迄今为止对TeV天空进行最深的宽视场调查的望远镜。通过原型设计和在HAWC站点部署测试阵列，实现了设计和成本的改进。在整个开发过程中，成本估算和设计灵敏度大致保持不变。目标是在阵列建设期间开始采集数据，并在大约三年内上线。这将允许HAWC在费米任务进行时运行。更广泛的影响：HAWC是一种全天候仪器，它将具有灵敏度，可以将卫星发现的源的测量扩展到TeV能量。HAWC将以Milagro强大的外展记录为基础，将这一令人兴奋的研究领域带给学生和公众。由于HAWC是一个美墨联合项目，这将是一个极好的机会，吸引有才华的西班牙裔学生进入粒子天体物理学和一般物理学领域。该小组制作了一个关于HAWC的外联视频，以及关于HAWC和粒子天体物理学的西班牙语和英语网络材料。

This award will provide funds for the construction of the High Altitude Water Cherenkov (HAWC) gamma-ray observatory to be built at Sierra Negra in Mexico. The costs for hardware, engineering, and contract (nonscientist) labor to build HAWC are being provided here. The observations of HAWC will probe the most extreme environments in the Universe, providing a unique view of non-thermal processes in the Galaxy and beyond. The key science goals of HAWC are to: (a) Measure the spectrum of Galactic sources to the highest energies; (b) Map the Galactic diffuse gamma-ray emission from 1 TeV to 100 TeV measuring the cosmic-ray flux and spectrum across the Galaxy; (c) Study transient emission from active galactic nuclei (AGN); (d) Monitor the sky for 100 GeV emission from gamma-ray bursts; and (e) Search for new TeV physics with HAWC's unbiased sky survey. HAWC measurements have the potential to shed light on the fundamental symmetries of nature, including the search for Lorentz violation at extreme energies, the search for the dark matter in the universe, and the direct detection of massive relic particles.HAWC is an array consisting of 250 large water tanks, each instrumented with three photomultiplier tubes (PMTs) mounted on the bottom of the tank. The tanks will cover an area of ~20,000 square meters. The expanded detection, increased altitude and optical isolation of the detector elements lead to a 15-fold increase in sensitivity relative to Milagro, which performed the deepest wide-field survey of the TeV sky to date. Refinement of the design and cost has been achieved through prototyping and deploying a test array at the HAWC site. The cost estimate and design sensitivity have stayed roughly constant through the development process. The goal is to begin taking data while the array is under construction and to be online within approximately three years. This will allow HAWC to run while the Fermi mission is ongoing.Broader Impacts: HAWC is an all-sky instrument that will have the sensitivity to extend the measurement of satellite-discovered sources to TeV energies. HAWC will build on the strong outreach record of Milagro to bring this exciting field of research to students and the general public. Since HAWC is a joint US-Mexican project, this will be an excellent opportunity to attract talented Hispanic students to the field of Particle Astrophysics and to Physics in general. The group has developed an outreach video about HAWC and web materials about HAWC and Particle Astrophysics in both Spanish and English.