Gamma-rays are the highest energy form of electromagnetic radiation. Observations of astrophysical gamma-rays serve as probes of physical conditions and processes in the most extreme environments throughout the Universe, and can be used to test fundamental physics. This award supports scientists at the University of Utah to carry out gamma-ray astrophysics research using two complementary ground-based observatories. The Very Energetic Radiation Imaging Telescope Array System (VERITAS), located in southern Arizona, is designed to study high energy gamma-rays with very sensitive pointed observations. The High Altitude Water Cherenkov (HAWC) observatory, located on the slopes of the Sierra Negra in Mexico, is a continuously-operating array with a wide field of view that can observe two-thirds of the high energy gamma-ray sky every day. The University of Utah group will contribute to the operation and maintenance of VERITAS and HAWC and work on analysis and interpretation of the scientific data. The group will continue and expand their existing education and outreach activities using the on-campus South Physics Observatory, the high altitude Willard L. Eccles Observatory, and the Star Base Utah Observatory for both public education and student projects. They will build new connections to Utah senior citizens through courses developed for the University's Osher Institute.
The University of Utah group will use VERITAS to extend detections of flaring active galactic nuclei to higher redshifts, setting more stringent limits on the flux of extragalactic background light. Long-term VERITAS observations of high mass x-ray binaries as well as other galactic binaries and microquasars will be used to explore similarities in their time-dependent gamma-ray emission, while observations of Galactic supernova remnants will be used to explore the origin of galactic cosmic rays. Using both VERITAS and HAWC synergistically, the group will explore the origin of cosmic rays in diffuse supernova remnants and pulsar wind nebulae, and enhance the search for neutralino Dark Matter emission from unidentified high galactic latitude VHE gamma-ray sources.
