Upper limits on the total cosmic-ray luminosity of individual sources

TL;DR

This study establishes upper limits on the total ultra-high-energy cosmic-ray luminosity of five individual sources by analyzing gamma-ray flux data and modeling cosmic ray propagation, providing constraints on their energetic outputs.

Contribution

It introduces a method to derive UHECR luminosity limits from gamma-ray observations for individual sources, considering various emission mechanisms.

Findings

Upper limits on UHECR luminosity for five sources were determined.

Gamma-ray flux measurements constrain the cosmic-ray luminosity estimates.

Upper limits on proton luminosity were also established for all studied sources.

Abstract

In this paper, upper limits on the total luminosity of ultra-high-energy cosmic rays (UHECR) (E > $10^{18}$ eV) are determined for five individual sources. The upper limit on the integral flux of GeV-TeV gamma-rays of a given source is used to extract the upper limit on the total UHECR luminosity. The correlation between upper limit on the integral GeVTeV gamma-ray flux and upper limit on the UHECR luminosity is established through the cascading process that takes place during propagation of the cosmic rays in the background radiation fields, as explained in reference [1]. Twenty-eight sources measured by FERMI-LAT, VERITAS and MAGIC observatories have been studied. The measured upper limit on the GeV-TeV gamma-ray flux is restrictive enough to allow the calculation of an upper limit on the total UHECR cosmic-ray luminosity of five sources. The upper limit on the UHECR cosmicray luminosity of these sources is shown for several assumptions on the emission mechanism. For all studied sources an upper limit on the ultra-high-energy proton luminosity is also set.