GeV/TeV Astrophysics Research using the VERITAS Observatory

VERITAS-4天文台是发现和研究甚高能GeV/TeV能量伽马射线辐射天体物理源的新一代仪器，目前正在亚利桑那州图森附近接近完工。这笔赠款支持犹他大学的伽马射线小组完成VERITAS-4天文台的建造，并在VERITAS-4观测站的运行阶段利用VERITAS-4观测站进行观测和进行数据分析。天文台由一个由研究型大学组成的国际联盟管理，这些大学建造了VERITAS-4望远镜，资金来自国家科学基金会、美国能源部、史密森基金会、PPARC、NSERC和爱尔兰企业组织。Veritas的合作机构包括史密森天体物理天文台、芝加哥大学、犹他大学、普渡大学、华盛顿大学(圣路易斯)、加州大学洛杉矶分校、爱荷华州立大学、麦吉尔大学(加拿大)、利兹大学(英国)和都柏林大学学院。VERITAS-4天文台由四个直径12米的大气成像切伦科夫望远镜(IACT)组成的阵列，这是一种光学反射器，可以观察VHE伽马射线与地球大气层相互作用时发出的微弱切伦科夫光的闪光。在过去15年里，已确认的VHE发射源的数量从单个天体(蟹状星云)发展到数十个天体；新一代Hess天文台(其灵敏度类似于VERITAS)最近在南半球的观测使已知源的数量增加了两倍多，并发现了新的一类源，包括银河系中心凹陷A*的发射、超新星残骸的发射、X射线双星的发射、以及在这些能量下观测到的最大红移的活动星系核的发射。在这项拟议的工作期间，VERITAS-4天文台预计将在北半球的天空中发现同样丰富的新来源和现象。GeV/TeV能量伽马射线是天体物理物体中能量最高的过程的独特探测器。这种非热辐射追踪了与blazar有关的喷流中的相对论过程，blazar是具有超大质量(10**6太阳质量)中心黑洞的河外星系，通过附近吸积物质的引力流入为观察者指向的相对论喷流提供动力。此外，GeV/TeV能量伽马射线是银河系内宇宙线相互作用的独特示踪剂，可以提供我们银河系内宇宙线受限的证据，以及与宇宙辐射场和巨型分子云相互作用的证据。因此，它们可以作为星际和银河系间辐射和物质场的有效探测器，对于限制早期宇宙中的恒星形成以及随后的银河系演化至关重要。犹他大学参与了社区、大学、州和国家各级的教育推广计划。犹他大学伽马射线小组通过赞助学年学生研究机会、惠普尔天文台致力于Veritas项目的暑期实习以及犹他大学的新教育举措，制定了一项面向本科生的强有力的外展计划。

The VERITAS-4 observatory, a next generation instrument for the discovery and study of astrophysical sources of Very High Energy (VHE) GeV/TeV energy gamma-ray radiation, is currently nearing completion near Tucson, AZ. This grant supports the University of Utah's Gamma Ray Group to complete construction of the VERITAS-4 Observatory and to perform observations with and carry out analysis of data from the VERITAS-4 observatory during its operational phase. The observatory is managed by an international consortium of research universities who have constructed the VERITAS-4 telescopes with funding from the National Science Foundation, the US Department of Energy, the Smithsonian Foundation, PPARC, NSERC, and Enterprise-Ireland. VERITAS Collaborating institutions include Smithsonian AstrophysicalObservatory, the University of Chicago, the University of Utah, Purdue University, Washington University (St. Louis), UCLA, Iowa State University, McGill University (Canada), Leeds University (UK), and University College Dublin. The VERITAS-4 Observatory consists of an array of four 12 meter diameter Atmospheric Imaging Cherenkov Telescopes (IACTs), optical reflectors which observe faint flashes of Cherenkov light emitted as VHE gamma rays interact with the Earth's atmosphere. Over the past 15 years, the number of confirmed VHE emitters has grown from a single object (the Crab Nebula) to tens of objects; recent observations in the Southern Hemisphere by the next generation HESS Observatory (with sensitivity similar to VERITAS) have more than tripled the number of known sources, and have discovered new classes of sources, including emission from the Galactic Center Sag A*, emission from supernova remnants, emission from X-ray binaries, and emission from Active Galactic Nuclei at the largest redshift ever observed at these energies. A similar wealth of new sources and phenomena are expected to be discovered in the Northern Hemisphere sky with the VERITAS-4 Observatory over the period of this proposed work. GeV/TeV energy gamma rays are unique probes of the most energetic processes in astrophysical objects. This non-thermal radiation traces relativistic processes in jets associated with Blazars, extragalactic galaxies with supermassive (10**6 solar mass) central black holes that power the observer-pointed relativistic jets through gravitational infall of nearby accreting material. Also, GeV/TeV energy gamma rays are unique tracers of cosmic ray interactions within the Galaxy, and can provide evidence of cosmic ray confinement within our Galaxy, and of interactions with cosmological radiation fields and Giant Molecular clouds. Consequently, they can serve as effective probes of interstellar and intergalactic radiation and matter fields, essential for providing constraints on star formation within the early Universe as well as subsequent Galactic evolutionThe University of Utah participates in Educational Outreach programs in the community, University, statewide and national levels. The University of Utah Gamma Ray Group has developed a strong outreach program to undergraduate students by sponsoring academic year student research opportunities, summer internships at the Whipple Observatory working on the VERITAS project, and new educational initiatives at the University of Utah.