Speaker
Description
Extremely energetic cosmic rays (ExECRs) hold strong potential for determining the origin of extra-galactic cosmic rays. Their interactions with the cosmic microwave background restrict their horizon enough that their propagation can be considered local, unaffected by cosmological evolution. Furthermore, the deflections caused by extra-galactic magnetic fields (EGMFs) are reduced for ExECRs, allowing a stronger correlation between arrival direction and source location. From the theoretical point of view, these ExECRs require methods that are fast and efficient enough to enable event-by-event estimation of the likely distance and direction of origin.
Employing a stochastic analytic framework for describing cosmic ray interactions with analytic probability distributions, the potential for GCOS to uncover the origins of extra-galactic cosmic rays is evaluated. The probability distributions for the origin distance and angular deviation are shown for a number of source-observed nuclei combinations. The composition and angular resolutions needed to separate these hypothesis are contrasted with the planned specifications for GCOS. The framework is implemented in a package called CRISP (Cosmic Ray Interactions for Stochastic Propagation) in preparation for release to the community soon.