WoU-MMA: Investigation of Extragalactic Gamma-rays - Photon Origin, Extragalactic Field Interactions and Ground-based Detection

The overarching objective of this award is to improve our understanding of extragalactic gamma-ray photons from blazars and the detection of these photons by Imaging Atmospheric Cherenkov Telescopes (IACTs). The project will study the highest energy electromagnetic radiation from blazars in multiple ways. Gamma-ray emitting blazars are among the most extreme astrophysical sources within the Universe, harboring energetic phenomena far beyond that attainable by terrestrial accelerators. These objects are prime laboratories for multi-messenger astrophysics, as they are hypothesized as progenitors of every messenger so far measured, including photons, neutrinos, ultra-high-energy cosmic rays and gravitational waves. This multi-component project uses data from the VERITAS and prototype Schwarzschild-Couder (pSCT) telescopes to increase our understanding of gamma-ray photons from blazars by probing fundamental and observational questions about the entire gamma-ray photon path, from the creation of the photon and its interactions along its extragalactic travels, to the detection of the gamma-ray by current and future IACTs. Specific investigations focus on production of gamma rays within the blazar itself, quantification (by proxy) of the photon interactions along the extragalactic path, and improvement of gamma-ray detection by current and future IACTs. The project will help to educate and train the next generation of US gamma-ray astrophysicists, supporting a graduate student and undergraduates as they take part in cutting edge research. The team will explore ways to improve the diversity, equity and inclusion practices within large scientific collaborations such as VERITAS and the future Cerenkov Telescope Array. This project advances the objectives of "Windows on the Universe: the Era of Multi-Messenger Astrophysics", one of the 10 Big Ideas for Future NSF Investments. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.