Particle Astrophysics at the Energy Frontier at Auger South

Ohio State University, The, Columbus OH

Investigators

Abstract

The southern Pierre Auger Observatory is a 3000 square km hybrid cosmic ray detector located near Malargüe, Argentina. It consists of an array of 1600 water Cherenkov surface detectors together with four fluorescence detector sites, and is now fully completed and commissioned. This award will enable a research program focused on maximizing the scientific payoff from this detector. Key scientific questions that this group is attempting to address include: [1] What astrophysical objects produce the highest energy cosmic rays? [2] What constraints can be derived on Galactic and extragalactic magnetic fields from observations of cosmic rays? [3] What is the composition of the highest energy cosmic rays? [4] Are the interactions of the cosmic ray primaries consistent with existing models of high-energy interactions, or are there hints of new particle physics? One area of emphasis in the group's data analysis includes studies of the effect of Galactic magnetic fields on cosmic ray arrival directions and the implications of this for Galactic field models, cosmic ray origins, and composition. Another area of study is the distribution of the depth of shower maximum and related shower variables as probes of cosmic ray composition and interactions. They are also working on the study of microwave bremsstrahlung from air showers as a possible new detection technique that would enable 24/7 fluorescence-like measurements. The group is involved in outreach efforts to central Ohio high school students, which has contributed to student interest in pursuing college degrees in STEM disciplines. The Auger project is truly international, and contributes to international cooperation and understanding in the sciences.