UHECRs Are Not Protons (If you go Away)

arXiv

``The energy spectrum, composition and arrival directions of ultrahigh energy cosmic rays (UHECRs) with energy above the cosmic ray ankle, measured by the Pierre Auger Observatory, are inconsistent if their origin is assumed to be extragalactic. Their observed properties, however, are those expected from UHECRs accelerated by the highly relativistic jets emitted in Galactic gamma ray bursts, most of which are beamed away from Earth. If this alternative interpretation is correct, the observed break in the energy spectrum of UHECRs around 50 EeV is not the Greisen-Zatsepin-Kuzmin cutoff but the energy threshold for free escape of ultrahigh energy iron cosmic rays from the Galaxy. Above their free-escape threshold-energy, UHECR nuclei should point back to their Galactic sources or their remnants.''

Fe Cosmic Rays!

Good work Álvaro de Rújula!

On the other hand, PAO's data become a mess. I sort of like the simpler view prior to this Spaniard and his friends' work.

So it goes.

Julio and Álvaro are killing us. On the other hand I like Barbra better.