The most energetic cosmic rays and their possible sources

TL;DR

This paper reviews observations of ultra-high-energy cosmic rays, confirms measurement methods, compares energy estimates, and explores potential sources like active galactic nuclei, providing insights into their origins and properties.

Contribution

It offers a detailed analysis of cosmic ray measurements, validates energy estimation techniques, and investigates the connection between cosmic rays and active galactic nuclei as their sources.

Findings

Confirmation of s(600) as a reliable energy estimator.

Calculated energy estimates are ~1.7 times smaller than experimental values.

Pointing directions of air showers align with nearby active galactic nuclei.

Abstract

The primary cosmic rays particles with energies above 10**20 eV have been observed at many extensive air shower arrays since the beginning of observations over 40 years ago. The validity of measurements of signal s(600) used as energy estimation parameter at the Yakutsk array has been confirmed. Our calculations show that the width of the time pulses increases from nearly 100 ns at a distance of 100 m from the shower axis up to 4 - 5 $\mu$s at 1500 m. The calculated estimate of energy of extensive air shower is ~ 1.7 times smaller than the experimental estimate for the same value s(600). The pointing directions of extensive air showers observed at the Pierre Auger Observatory were fitted within +-3.1**o with positions of the nearby active galactic nuclei from the Veron-Cetty and P. Veron catalog. The cosmic ray luminosity of the active galactic nuclei which happened to be a source of the particular cosmic ray event constitutes a fraction ~10**-4 of the optical one if only cosmic ray particles with energies above 6*10**19 eV are produced. If produced cosmic ray particles have a spectrum up to ~ 100 GeV then the cosmic ray luminosity of the active galactic nuclei should be much higher than the optical one.