The current recorded signals of ultrahigh-energy $\gamma$-rays may come from EeVatrons in the galaxy

TL;DR

This paper proposes that ultrahigh-energy gamma-ray signals may originate from galactic EeVatrons, with the gluon condensation effect enhancing proton interactions, explaining observed gamma-ray spectra and implying the existence of extremely energetic cosmic accelerators.

Contribution

It introduces the gluon condensation effect as a key factor in explaining gamma-ray spectra and the existence of EeVatrons in the galaxy, extending the understanding of cosmic ray acceleration.

Findings

G106.3+2.7's gamma-ray spectrum explained by hadronic model with gluon condensation

Gluon condensation enhances proton-proton cross section, compensating weak flux

Proposes efficient energy conversion from kinetic energy to gamma-rays in the universe

Abstract

A hard $\gamma$-ray spectrum of supernova remnant G106.3+2.7 can be explained by using the hadronic model with the gluon condensation effect. This implies that not only PeVatrons but also EeVatrons generally exist in the universe including our galaxy, and they can accelerate protons to beyond "ankle" ($10^{19}~eV$). Although these proton beams are very weak in the galaxy and cannot be observed individually on the earth, the gluon condensation effect may greatly enhance the proton-proton cross section, which can compensate for the weak proton flux and produce the observed $\gamma$-rays. We also show that the gluon condensation effect in proton provides an efficient conversion mechanism for kinetic energy into $\gamma$-rays in the universe.