Study of the Highest Energy Cosmic Rays with the Pierre Auger Observatory

The Pierre Auger Observatory (PAO) is a large International endeavor aimed at the study of Ultra?High Energy Cosmic Rays (UHECRs). PAO is a hybrid experiment with a large array of surface detectors measuring the footprint of an extensive air shower when it reaches the Earth and with multiple fluorescence telescopes measuring the shower in the space above. They have started deploying a low energy extension to study the galactic to extra?galactic transition. The latest PAO results have confirmed the long anticipated GZK suppression in the spectrum due to interactions with the microwave background. However, the sources of the highest energy particles and questions about how they are accelerated in the first place are among the most important topics in particle astrophysics today. One suspected source is Active Galactic Nuclei, which are among the most energetic objects known in the Universe.

This award will fund the continued participation of this investigator in the areas of detector calibration, maintenance and operation, and analysis of PAO data. His group employs undergraduate students in detector construction, operation, atmospheric monitoring, data analysis and software development. The group participates in the well?established PAO outreach program in Argentina with activities including the preparation of materials and presentations at the Visitor?s Center, public talks, visits to schools, science fairs, and courses for teachers and students.