WoU-MMA: Operations of VERITAS in the Epoch 2025 to 2028

Gamma-rays represent the highest energy form of electromagnetic radiation. Observing gamma-rays from astrophysical sources allows scientists to explore the physical conditions and processes occurring in some of the most extreme environments in the Universe. These high-energy rays can be utilized to test fundamental principles of physics and are significant in the context of multi-messenger astrophysics. The Very Energetic radiation Imaging Telescope Array System (VERITAS), situated in southern Arizona, stands as the most sensitive observatory in the world for studying very high-energy gamma rays. This funding award will support the continued operation of VERITAS for one year. During this period, the facility will execute a program to conduct high-sensitivity observations of both galactic and extragalactic sources. This initiative aims to address important scientific questions in both Galactic and extragalactic astrophysics, as well as explore themes in multi-messenger and time-domain astrophysics. Additionally, this award allocates resources for a new prototype telescope at the VERITAS site. This prototype is intended for future use in the upcoming Cherenkov Telescope Array Observatory (CTAO), which represents the next generation of gamma-ray observatories. VERITAS possesses unique capabilities and offers a broad range of research opportunities for its user community. The funding also provides transformative opportunities for the professional development of emerging scientists. This includes supporting fieldwork at VERITAS, advanced training, hardware and software development, and new internship opportunities. Efforts related to the CTAO will secure access to this next-generation facility for the entire U.S. scientific community. Furthermore, this award promotes engagement with the public in science through collaborative initiatives with the F.L. Whipple Observatory Science Center. VERITAS is an array of four 12-meter atmospheric-Cherenkov telescopes and will be the state of the art until early CTAO operations in ~2027. This award will enable in-depth γ-ray studies of a wide variety of Galactic and extragalactic very-high-energy (VHE; E > 100 GeV) emitters to be performed. Searches are planned for VHE signals from potential sources of all known astronomical messengers: photons, neutrinos, cosmic rays, and gravitational waves. VERITAS is the only observatory at its longitude capable of detecting transient VHE emission from high-redshift extragalactic sources associated with multi-messenger events. VERITAS studies leverage major observatories at all energies and have broad implications beyond the physics of the objects themselves, addressing a range of issues in fundamental physics including cosmology, cosmic-ray origin, and the nature of dark matter. An intensity-interferometry program focused on stellar physics will also be enabled. The support for the CTAO prototype effort enables critical instrument development and allows scientists to fully understand this novel telescope, to conclusively demonstrate that it performs as expected and to optimize its final design. 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.