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一个空中切伦科夫望远镜（ACT），目的是研究非常高能（VHE）伽马射线的谨慎天体物理源。该仪器将由一组抛物面镜组成，聚焦处有光电倍增管，可以探测到大气中一小部分VHE相互作用产生的光。该实验将揭示宇宙射线的起源，如果存在奇异辐射，也可能揭示奇异辐射的来源。ACT将补充现有的南极气淋实验（SPASE），并将SPASE的能量阈值降低两到三个数量级。SPASE可以调查大部分南部天空，而ACT将能够关注可疑活动的小区域。位于南极的位置将允许ACT在恒定厚度的大气中长时间（数周到数月）观察单个物体，而中纬度位置一次只能观察一个给定物体几个小时。由于大气是探测器，因此通过恒定厚度进行观测的重要性再怎么强调也不为过。该项目是威斯康星大学、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（佛罗伦萨，意大利）的合作项目。它是由美国国家科学基金会极地项目和物理部、意大利南极项目、威斯康星校友研究基金会和史密森天体物理天文台共同资助的。

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 SPASE. 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 of 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 Divisions of Polar Programs and Physics, the Italian Antarctic Program, the Wisconsin Alumni Research Foundation and the Smithsonian Astrophysical Observatory.