Above a certain threshold, this type of radiation cannot (*) travel farther than 100Megaparsecs due to collisions with the CMB.
The "knee" range is an unexplained connection between two sources of this radiation, and thistype of radiation can interact with the relic neutrino background, causing "Z-bursts". The airfluorescence technique is used to detect this type of radiation. The charge of the primary type of thisradiation was inferred to be positive due to the suppression of this when it comes from the east, calledthe east-west effect. Above a certain threshold, this type of radiation cannot (*) travel farther than 100Megaparsecs due to collisions with the CMB. That threshold is the GZK limit, and like gamma ray bursts,the origin of this radiation is explained by charged particles being accelerated by a magnetized shock, orFermi acceleration. For 10 points, name this highest energy radiation which consists mainly of protons andtakes its name from its origin in space.
The "knee" range is an unexplained connection between two sources of this radiation, and thistype of radiation can interact with the relic neutrino background, causing "Z-bursts".
cosmic radiation [or cosmic rays; accept any type of energy cosmic ray, such as low energy, extremely high energy, etc.; do not accept galactic or extragalactic cosmic rays]