Collaborative Research: WoU-MMA: IceCube Data Analysis in the U.S. 2026-2029

The IceCube Neutrino Observatory has opened a new window on the Universe and created a new branch of astrophysics. IceCube is an unconventional telescope which consists of sensors embedded in nearly 1,000 megatons of deep, clear Antarctic ice near the geographic South Pole to detect subatomic particles called neutrinos. As the world’s largest operating neutrino detector, IceCube forms a cornerstone of the United States Antarctic Program. Neutrinos can offer a glimpse into some of the most energetic processes in our Universe, including the dense cores of astrophysical objects from which visible light may not be able to escape. Since construction of IceCube was completed in 2011, we have discovered high energy neutrinos from outside of our galaxy, as well as neutrino emission from the plane of our own Milky Way. We have coordinated our observations with other types of telescopes, including gamma ray satellite observatories and ground based optical telescopes to identify and study their origins. We have also used our instrument to study properties of neutrinos themselves. In addition, we monitor the sky for supernovae originating from within our Galaxy. Our physics program now spans ten orders of magnitude in neutrino energy. This grant provides funding for scientists at U.S. universities to continue to analyze IceCube data, capitalizing on the large investment in this groundbreaking NSF major facility. This grant provides funding for scientists at U.S. universities to analyze data from the IceCube Neutrino Observatory. Since construction of the IceCube was completed in 2011, we have detected a flux of high energy neutrinos of astrophysical origin with an energy spectrum extending to greater than 10 PeV, and established neutrinos as a key component of multimessenger astrophysics. The key to IceCube’s success is not merely the accumulation of data over time. Intensive calibration activities and continuous innovation in analysis methods have enabled us to exceed our initial design sensitivity and even expand our activity into new areas of inquiry. Our physics program now spans ten orders of magnitude in neutrino energy. In the austral summer of 2025-2026, we installed the IceCube Upgrade, the first major addition to the hardware in 15 years. The resulting enhancement to our low energy sensitivity will establish IceCube as the leading instrument in neutrino oscillation physics until after HyperK commences data taking in 2028. In addition, calibrations enabled by the Upgrade have the potential to increase the power of our extensive existing dataset through improved reconstruction and reduced systematics. An intensive collaborative effort will be required to perform the calibration studies and develop the reconstruction algorithms required to realize its transformative scientific potential. In addition to the effort required to fully realize the power of the new hardware, this funding will allow the collaboration to continue to more fully exploit our data through the use new techniques such as neural networks. With the ongoing data collection by IceCube and the enhanced dataset produced by the Upgrade, we will continue to pursue further identification of neutrino sources both with IceCube data and with multi-messenger studies, extending neutrino astronomy higher and lower in energy, characterizing the diffuse neutrino flux, exploring the fundamental properties of neutrinos, monitoring the Galaxy for supernova explosions, and searching for signals of physics beyond the standard model. 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.