Violation of the Greisen-Zatsepin-Kuzmin cutoff: a tempest in a (magnetic) Teapot? Why cosmic ray energies above 10(20) eV may not require new physics.
نویسندگان
چکیده
The apparent lack of suitable astrophysical sources for the observed highest energy cosmic rays within approximately 20 Mpc 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 microG 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.
منابع مشابه
Comment on “ Violation of the Greisen - Zatsepin - Kuzmin Cutoff : A Tempest in a ( Magnetic ) Teapot ? Why Cosmic Ray Energies above 10 20 eV May Not Require New
In a recent letter [1] with the same title, Farrar and Piran offered an explanation for the near isotropy of the arrival directions [2] of ultrahigh energy cosmic rays (UHECRs) and the apparent absence [3] of the so called ‘GZK cutoff’ in their spectrum around 10 eV due to pion photoproduction on the cosmic background radiation (CMB) that was predicted independently by Greisen [4] and by Zatsep...
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عنوان ژورنال:
- Physical review letters
دوره 84 16 شماره
صفحات -
تاریخ انتشار 2000