WoU-MMA: Exploring the Extreme Universe with VERITAS and CTA

Advanced studies of high-energy gamma-rays make it possible to probe the sites of relativistic particle acceleration and the underlying mechanisms. Gamma-ray observations with the Very Energetic Radiation Imaging Telescope System (VERITAS), located at the Fred Lawrence Whipple Observatory in southern Arizona, provide the opportunity for a diverse research program to study Galactic and extragalactic particle accelerators. This award renews support for researchers at the University of Delaware to conduct studies of supernova remnants, newly identified petaelectronvolt (PeV) gamma-ray emitters, and precision measurements of bright nearby active galactic nuclei. The team will continue providing leading contributions to the VERITAS operations, calibration, and data analyses, and to the development of the next generation Cherenkov Telescope Array (CTA). The group will continue education and outreach activities through mentoring programs of undergraduate students, engagement of high school students through Masterclasses, and co-leading the two-week high-energy astrophysics Fermi Summer School. VERITAS and the future CTA utilize imaging Cherenkov telescopes to provide high-sensitivity to very high-energy (100 GeV – 30 TeV) gamma-ray observations of Galactic and extragalactic sources. Gamma-ray emission has been used to reveal where relativistic particle acceleration occurs, but the underlying acceleration mechanisms and the connections between the accelerators and the origin and properties of cosmic rays remain unclear. Observing targets include supernova remnants (SNRs) as sources of multi-messenger events (gamma-rays, cosmic rays, and neutrinos), and searches for Galactic PeV accelerators (PeVatrons). Improvements in the treatment of off-axis images in VERITAS will optimize high-energy analyses of PeVatron targets and extended source searches. Applying these new techniques will make it possible to study TeV-bright, extended SNRs where the measured spectrum, or upper limit, will test leading models for leptonic or hadronic acceleration scenarios. This project advances the goals of the NSF Windows on the Universe Big Idea. 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.