Region of Excessive Flux of PeV Cosmic Rays in the Direction Toward Pulsars PSR J1840+5640 and LAT PSR J1836+5925

TL;DR

This study identifies a region of excessive PeV cosmic ray flux aligned with two pulsars, suggesting pulsars may significantly contribute to Galactic cosmic rays at these energies.

Contribution

It provides evidence linking specific pulsars to localized excesses in cosmic ray flux, highlighting pulsars as potential sources of PeV cosmic rays.

Findings

Region of excess flux detected with significance up to 4.5sigma.

Excess aligned with pulsars PSR J1840+5640 and LAT PSR J1836+5925.

Supports pulsars as contributors to Galactic PeV cosmic rays.

Abstract

An analysis of arrival directions of extensive air showers (EAS) registered with the EAS MSU and EAS-1000 prototype arrays has revealed a region of excessive flux of PeV cosmic rays in the direction toward pulsars PSR J1840+5640 and LAT PSR J1836+5925 at significance level up to 4.5sigma. The first of the pulsars was discovered almost 30 years ago and is a well-studied old radio pulsar located at the distance of 1.7pc from the Solar system. The second pulsar belongs to a new type of pulsars, discovered by the space gamma-ray observatory Fermi, pulsations of which are not observed in optical and radio wavelengths but only in the gamma-ray range of energies (gamma-ray-only pulsars). In our opinion, the existence of the region of excessive flux of cosmic rays registered with two different arrays provides a strong evidence that isolated pulsars can give a noticeable contribution to the flux of Galactic cosmic rays in the PeV energy range.