Particle Astrophysics with the VERITAS Detector

这项申请是为了继续支持麦吉尔小组在Veritas伽马射线天体物理项目中的工作。VERITAS(非常能量成像望远镜阵列系统)是一个由四个12米望远镜组成的阵列，使用成像大气切伦科夫技术研究能量在100GeV到30TeV之间的天体物理伽马射线；它是世界范围内运行的三个主要探测器之一。望远镜探测到由于高层大气中伽马射线的相互作用而产生的带电粒子“簇射”产生的切伦科夫光；切伦科夫光传播到地面(即使带电粒子簇射在大气中被吸收得更高)，并由快速光电管组成的相机成像。Veritas研究的伽马射线-能量超过100GeV-是由宇宙中一些最极端的环境中更高能量的带电粒子产生的，包括超新星遗迹和活动星系核(星系中有一个超大质量黑洞，其自旋轴大致指向我们的视线)。自2007年首次亮相以来，VERITAS已经探测到60多个天体物理源(其中大约一半是新发现的)，包括这两个来源类别以及其他几个来源类别。此外，还有其他可能的、更奇异的高能伽马射线来源，包括暗物质粒子的湮灭和原始黑洞的蒸发。对更经典的天体物理源的研究以及对更多推测信号的搜索可以提供关于粒子物理的信息，其能量远远高于当今加速器提供的信息。VERITAS还与多波长和多信使伙伴密切合作，对特别感兴趣的来源进行协调观测。我们定期与无线电、光学和X射线领域的团队合作。更接近我们自己的能量范围的是NASA费米伽马射线太空望远镜(在GeV制度下的MeV到10‘S)和地面HAWC全天探测器(在&gt；10TeV制度下)。费米每天多次看到整个天空(尽管由于其体积小，灵敏度较低)，而HAWC每天都能看到整个北半球--它们都可以用来触发视场较小但更灵敏的VERITAS仪器。此外，与我们的粒子物理兴趣非常相关的是冰立方南极中微子探测器和LIGO引力波探测器；VERITAS有一个与这两台仪器进行协调观测的计划。VERITAS自2007年开始运行，麦吉尔小组自2000年中的S以来一直是合作的一部分。该仪器非常容易理解和稳定，尽管我们正在继续升级它的新功能。我们预计，它将再运行几年，继续提供高质量的科学成果。

This application is for continued support for the McGill group in the VERITAS gamma-ray astrophysics project. VERITAS (the Very Energetic Imaging Telescope Array System) is an array of four twelve-meter telescopes that studies astrophysical gamma rays with energies between 100 GeV and 30 TeV, using the Imaging Atmospheric Cherenkov Technique; it is one of three major detectors in operation world-wide. The telescopes detect the Cherenkov light from the charged particle 'showers' that arise due to interactions of the gamma rays in the upper atmosphere; the Cherenkov light propagates to the ground (even though the charged particle showers are absorbed much higher in the atmosphere) and is imaged with cameras composed of fast phototubes. The gamma rays that VERITAS studies - at energies above 100 GeV - are produced by even-more-energetic charged particles in some of the most extreme environments in the Universe, including supernova remnants and active galactic nuclei (galaxies harbouring a super-massive black hole whose spin axis is approximately pointed along our line-of-sight). Since its debut in 2007, VERITAS has detected more than 60 astrophysical sources (approximately half of those being new discoveries), including both of these source classes as well as several others. In addition, there are other possible, more exotic sources of high-energy gamma rays, including annihilation of dark-matter particles and evaporation of primordial black holes. The study of the more-classical astrophysical sources as well as the search for more speculative signals can provide information about particle physics at energies well above those available at today's accelerators. VERITAS also works closely with multi-wavelength and multi-messenger partners to carry out coordinated observations of particularly interesting sources. We regularly collaborate with groups working in the radio, optical, and X-ray regimes. Closer to our own energy range are the NASA Fermi Gamma-ray Space Telescope (in the MeV to 10's of GeV regime) and the ground-based HAWC all-sky detector (in the > 10 TeV regime). Fermi sees the entire sky multiple times per day (albeit at low sensitivity due to its small size) and HAWC sees the entire northern hemisphere each day - they can both be used to trigger the smaller-field-of-view but more sensitive VERITAS instrument. In addition, and very germane to our particle physics interests, are the IceCube South Pole neutrino detector and the LIGO gravitational wave detector; VERITAS has a program of coordinated observations with both of these instruments.  VERITAS has been in operation since 2007, and the McGill group has been a part of the collaboration since the mid 2000's. The instrument is very well-understood and stable, although we continue to upgrade it with new capabilities. We anticipate that it will operate for several more years with continued high-quality scientific output.