Fermi Gamma-ray Space Telescope

Developing a Pass 8 Cosmic-Ray Proton Event Class

David Green
Elizabeth Hays on behalf of the LAT Collaboration

Abstract:

The Pass 8 improved gamma-ray simulation and reconstruction package for the Large Area Telescope (LAT) on the Fermi Gamma-ray Space Telescope has drastically enhanced the ability of the LAT to perform gamma-ray science. The Pass 8 improvements have also allowed for the development of a new cosmic-ray proton analysis. Using these new algorithms, we are able to reconstruct directions and create a new proton event selection which can be used for future studies, including spectral and anisotropy analyses. This developing event selection has a high acceptance with energies from 50 GeV to over 1 TeV and, with over 6 years of data, will give high statistics for future analyses. Currently, energy reconstruction and systematic errors in the acceptance are being investigated. An anisotropy study is of interest because of weak dependence on these factors. We present a detailed study of direction reconstruction and event selection for the Pass 8 proton analysis.