Astrophysics with Very High Energy Gamma Rays

高能伽马射线被用来研究宇宙中最极端的物体，如脉冲星、活动星系中心的黑洞和伽马射线爆发。宇宙伽马射线也可以成为超越粒子物理和宇宙学标准模型的新物理学的标志。研究高于约100千兆电子伏特(GeV)的超高能伽马射线，需要拥有数千平方米收集面积的地面探测器。这项研究将使用亚利桑那州南部的Veritas成像切伦科夫望远镜阵列来研究能量大于约100GeV的伽马射线。VERITAS的灵敏度比运行在该能量范围内的上一代仪器高出一个数量级以上，而且刚刚通过实质性的升级进一步提高了。有了这一奖项，加州大学圣克鲁斯分校的研究小组将使用VERITAS来探索两类最强大的已知伽马射线源的极端行为：伽马射线爆发和活动星系核。伽马射线暴的详细机制以及它们在其他高能现象中所起的作用仍在探索中。了解它们是否能够产生极高能量的伽马射线，将限制伽马射线爆发的模型和爆发环境的性质。同样，对活动星系核的超高能伽马射线辐射的测量可以探测喷流的性质，提供关于被加速的粒子和加速如何工作的关键信息。来自整个电磁光谱的数据将被收集起来，并用来拼凑出最完整的非常高能伽马射线行为的图像。这些数据还将用于研究与河外背景光碰撞产生的伽马射线吸收，这一过程将测试恒星形成和星系演化的宇宙学模型。广泛的影响：研究生和本科生在这项研究中发挥着重要作用。研究经验还将通过一个新的Lick天文台师范学院提供给加州大学教学计划中有抱负的科学教师和在职教师。研究人员与加州州立大学互动，培养本科生对研究和研究生教育的兴趣。VERITAS数据与其他波长的数据之间有重要的相互作用，特别是来自SWIFT和费米等卫星飞行任务的X射线和较低能量伽马射线数据。同时使用两种类型的数据比单独使用这两种数据可以学到更多的东西。

High-energy gamma-rays are used to study the most extreme objects in the Universe, such as pulsars, black holes at the center of active galaxies, and gamma-ray bursts. Cosmic gamma-rays can also be signatures for new physics beyond the standard models of particle physics and cosmology. Studies with very-high-energy gamma rays, above about 100 gigaelectron volt (GeV), require ground-based detectors with thousands of square meters of collection area. This research will use the VERITAS imaging Cherenkov telescope array in southern Arizona to study gamma-rays with energy greater than about 100 GeV. The sensitivity of VERITAS is more than an order of magnitude better than previous generation instruments operating in this energy range and has just been improved further by a substantial upgrade. With this award the University of California - Santa Cruz group will use VERITAS to explore the extreme behavior of the two most powerful known classes of gamma-ray source: gamma-ray bursts and active galactic nuclei. The detail mechanisms of gamma-ray bursts and the role they play in other high-energy phenomena are still being explored. Learning whether they are capable of creating very-high-energy gamma-rays will constrain gamma-ray burst models and properties of the burst environment. Similarly, measurements of the very-high-energy gamma-ray emission from active galactic nuclei probe properties of the jets, providing crucial information about the particles being accelerated and how the acceleration works. Data from across the electromagnetic spectrum will be gathered and used to assemble the most complete possible picture of very high-energy gamma-ray behavior. These data will also be used to study gamma-ray absorption by collisions with the extragalactic background light, a process that tests cosmological models of star formation and galaxy evolution.Broader Impact: Graduate and undergraduate students play an important part in this research effort. Research experiences will also be made available to aspiring science teachers in the Cal Teach program and in-service teachers through a new Lick Observatory Teachers Institute. The researchers interact with the California State University to foster undergraduate interest in research and graduate education. There is an important interplay between the VERITAS data and data from other wavelengths, particularly X-ray and lower energy gamma-ray data from satellite missions such as Swift and Fermi. More can be learned from both types of data used together than from either alone.