Neutrons (and Neutrinos) from the Galactic Center

The AGASA and SUGAR extensive air shower cosmic ray detectors both find tantalizing evidence of an anisotropic overabundance of cosmic rays towards the Galactic Center (GC) region that “turns on” around 10 eV. I demonstrate that the anisotropy can be explained by extremely high energy neutrons created near the GC through charge-exchange in proton-proton collisions (where the incident, high energy protons obey a ∼ E−2 power law). The Galactic center gamma ray detections by several instruments, most recently and significantly HESS, provide strong corroborative evidence for this mechanism. This scenario will be tested in the future through direct detection of the neutrons by AUGER and, indirectly, by GC neutrino detection by km-scale neutrino telescopes including IceCube. Finally, I argue that the required shock acceleration is probably occuring in the shell of Sagittarius A East, an unusual supernova remnant located very close to the GC.