Observation of Very High Energy Gamma Ray Sources from the South Pole

该项目将在南极站开发和运行空气切伦科夫望远镜(ACT)，目的是研究非常高能量的伽马射线的谨慎天体物理来源。该仪器将由一系列抛物面反射镜组成，焦点处有光电倍增管，可以探测到小体积大气中VHE相互作用产生的光。这项实验将阐明宇宙射线的起源，如果存在外来辐射的话，还可能揭示这种辐射的来源。ACT将补充现有的南极空气簇射实验(SPASE)，并将空间能量阈值向下扩展两到三个数量级。Spase可以探测南方大部分天空，ACT将能够专注于疑似活动的小区域。南极的位置将允许ACT通过恒定厚度的大气在较长的时间内(几周到几个月)观察单个物体，而中纬度位置一次只允许对给定物体进行几个小时的观察。由于大气是探测器，因此通过恒定厚度观察的重要性怎么强调都不为过。该项目由威斯康星大学、普渡大学、哥伦比亚大学、特拉华大学巴托尔研究所、史密森天体物理天文台和佛罗伦萨大学(意大利菲伦泽)合作完成。它由NSF极地计划和物理部、意大利南极计划、威斯康星校友研究基金会和史密森天体物理天文台联合资助。

This project will develop and operate an Air Cherenkov Telescope (ACT) at South Pole Station for the purpose of studying discreet astrophysical sources of very high energy (VHE) gamma rays. The instrument will consist of an array of parabolic mirrors, with photomultiplier tubes at their foci, which can detect light from VHE interactions in a small volume of the atmosphere. The experiment will shed light on the origin of cosmic rays and possibly on sources of exotic radiation, if such radiation exists. ACT will complement the existing South Pole Air Shower Experiment (SPASE), and extend downward by two to three orders of magnitude the energy threshold of SPACE. SPASE can survey most of the southern sky, and ACT will be able to focus on small regions of suspected activity. The location at South Pole will allow ACT to view a single object for extended periods (weeks to months) through a constant thickness os atmosphere, while mid-latitude locations allow only a few hours of viewing at a time of a given object. Since the atmosphere is the detector, the importance of viewing through a constant thickness cannot be over emphasized. The project is a collaboration of the University of Wisconsin, Purdue University, Columbia University, Bartol Research Institute of the University of Delaware, Smithsonian Astrophysical Observatory and the University of Florence (Firenze, Italy). It is jointly funded by NSF's Division of Polar Programs and Physics, the Italian Antarctic Program, the Wisconsin Alumni Research Foundation and the Smithsonian Astrophysical Observatory.