CAREER: Discovery of Composition-Enriched Cosmic Ray Anisotropy with the IceCube Neutrino Observatory

Cosmic rays, which are mostly made up of atomic nuclei, carry energies that far exceed what we can achieve with our human-made accelerators. Despite this, many important details about where these rays come from, how they gain energy, and how they travel through space are still not fully understood. Unlike neutral particles, such as gamma rays or neutrinos, cosmic rays are affected by magnetic fields in galaxies.

This interaction complicates our ability to trace them back to their original sources. This project leverages the IceCube Neutrino Observatory located at the South Pole to examine extensive air showers that occur when cosmic rays collide with the Earth’s atmosphere. The project includes a strong educational component designed to engage high school and undergraduate students in practical physics research.

This will be achieved through outreach programs, and with the development of new curriculum modules that focuses on data science in physics. By introducing students to the latest machine learning techniques applicable to particle astrophysics, we aim to cultivate essential computational skills that will benefit them in both academic and professional settings.

This research combines data from IceTop, IceAct, and the IceCube in-ice detector to achieve the first enhanced measurement of cosmic-ray anisotropy in the southern hemisphere. Using data from various detection methods the project aims to better understand the mass composition, energy, and arrival directions of cosmic rays. The aim is to seek to deepen our understanding of cosmic-ray physics but it also holds the potential to advance the field of multi-messenger astrophysics and the study of interactions involving high-energy particles using a novel reconstruction framework that employs machine learning techniques to classify cosmic rays based on their mass composition.

This award will investigate also high-energy gamma rays in the PeV range, which can travel without being deflected, offering direct insights into the regions where cosmic rays originate. By cross-calibrating among the different detector components, systematic uncertainties can be minimized, while the implementation of new analysis techniques will lead to more accurate measurements of cosmic-ray properties.

These advancements will improve our understanding of the transition between galactic and extragalactic cosmic rays, providing significant insights into high-energy astrophysical processes.

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.