Particle Astrophysics with the VERITAS Detector

这个申请是为了资助麦吉尔大学继续参与VERITAS伽马射线天体物理学项目。VERITAS（高能辐射成像望远镜阵列系统）是世界上使用成像大气切伦科夫技术研究能量大于100 GeV的天体物理伽马射线的三个主要探测器之一。它由四台大型望远镜组成，用于探测高能伽马射线在高层大气中相互作用时产生的高能电子和正电子发出的紫外线和蓝色切伦科夫光。这种伽马射线是在极端环境中产生的，比如超新星遗迹和活跃的星系核。也可能有一些伽马射线来自更奇特的起源，比如星系核心暗物质粒子的湮灭，或者来自原始黑洞的蒸发。因此，它们可以提供能量超出地球上的加速器所能探测到的粒子物理信息。位于亚利桑那州南部的VERITAS阵列于2007年完工，并于当年9月开始了四架望远镜的观测。到目前为止，我们已经探测到超过63个天体物理伽马射线的来源，分为8类。其中大约一半是新发现的；其余的是确认。我们利用x射线、光学和射电望远镜以及费米伽玛射线空间望远镜的数据参与了多波长运动，费米伽玛射线空间望远镜覆盖的伽玛射线能量范围刚好低于VERITAS敏感的范围。一种新的地面全天空探测器，HAWC，其工作能量略高于VERITAS的范围，我们已经开始了与他们协调观测的计划。对冰立方中微子天文台和皮埃尔·奥格超高能宇宙射线天文台的有趣线索的后续研究是我们项目的一部分，类似的活动与LIGO引力波天文台有关。****** VERITAS探测器已经达到并超过了所有的设计规范，但我们仍在继续改进它。2009年，我们移动了四个望远镜中的一个来优化阵列布局，2012年夏天，我们用最新的高量子效率模型替换了望远镜相机中的所有光电倍增管，进一步提高了我们的灵敏度。安装了一个新的触发器，允许在较低的能量阈值下运行，改进的重建和背景抑制技术已纳入分析流程。在前几年的基础上，我们预计这将是一个高科学生产力和许多令人兴奋的新成果的时期

This application is for funding to support continued McGill participation in the VERITAS gamma-ray astrophysics project. VERITAS (Very Energetic Radiation Imaging Telescope Array System) is one of three major detectors world-wide that study astrophysical gamma rays with energies greater than 100 GeV, using the Imaging Atmospheric Cherenkov Technique. It consists of an array of four large telescopes designed to detect the ultraviolet and blue Cherenkov light emitted by energetic electrons and positrons produced when high-energy gamma rays interact in the upper atmosphere. Such gamma rays are produced in extreme environments such as supernova remnants and active galactic nuclei. There may also be gamma rays which come from more exotic origins such as annihilation of dark-matter particles in the cores of galaxies or from evaporation of primordial black holes. As such, they could provide information about particle physics at energies beyond what can be probed at Earth-bound accelerators. The VERITAS array, located in southern Arizona, was completed in 2007 and began four-telescope observations in September of that year. So far we have detected over 63 sources of astrophysical gamma rays, in eight classes. Approximately half of these are new discoveries; the remainder are confirmations. We have participated in multi-wavelength campaigns with data from X-ray, optical and radio telescopes, as well as the Fermi Gamma-ray Space Telescope which covers the gamma-ray energy range just below that where VERITAS is sensitive. A new ground-based all-sky detector, HAWC, operates at energies slightly higher than those in the VERITAS range and we have started a program of coordinated observations with them. Follow-ups on interesting hints from the IceCube neutrino observatory and the Pierre Auger ultra-high-energy cosmic-ray observatory are part of our program, with similar activities connected to the LIGO gravitational wave observatory.******The VERITAS detector has met and exceeded all design specifications but we continue to improve it. In 2009 we moved one of the four telescopes to optimize the array layout and in the summer of 2012 we replaced all photomultipliers in the telescope cameras with newly available high-quantum-efficiency models, further increasing our sensitivity. A new trigger has been installed to allow running at lower energy threshold and improved reconstruction and background-rejection techniques have been incorporated into the analysis stream. Based on the output from the previous years we expect a period of high scientific productivity and many exciting new results