Abstract
The apparent lack of suitable astrophysical sources for the observed highest energy cosmic rays within is the “Greisen-Zatsepin-Kuzmin (GZK) paradox.” We constrain representative models of the extragalactic magnetic field structure by Faraday rotation measurements; limits are at the level rather than the nG level usually assumed. In such fields, even the highest energy cosmic rays experience large deflections. This allows nearby active galactic nuclei (possibly quiet today) or gamma ray bursts to be the source of ultrahigh energy cosmic rays without contradicting the GZK distance limit.
- Received 24 June 1999
DOI:https://doi.org/10.1103/PhysRevLett.84.3527
©2000 American Physical Society