Are there pulsars in the knee ?

TL;DR

The paper evaluates whether pulsars like PSR B0656+14 can explain the cosmic ray knee at 3PeV, concluding they contribute only a small fraction and are unlikely the dominant source, but may explain certain air shower peaks.

Contribution

It provides quantitative estimates of pulsar contributions to PeV cosmic rays and assesses their role in the knee feature, challenging the idea of pulsars as the main source.

Findings

Pulsar B0656+14 contributes less than 15% to the cosmic ray intensity at the knee.

Pulsars like Geminga and Vela have minimal impact on the cosmic ray knee.

Pulsars may explain specific air shower peaks if particles are confined within the SNR.

Abstract

Recent findings indicate that the Monogem Ring supernova remnant and the associated pulsar PSR B0656+14 may be the 'Single Source' responsible for the formation of the sharp knee in the cosmic ray energy spectrum at $\sim$3PeV. We estimate the contribution of the pulsar B0656+14 to the cosmic rays in the PeV region and conclude that the pulsar cannot contribute more than 15% to the cosmic ray intensity at the knee. Therefore it cannot be the dominant source there and an SNR is still needed. We also examine the possibility of the pulsar giving the peak of the extensive air shower intensity observed from the region inside the Monogem Ring. The estimates of the gamma-ray flux produced by cosmic ray particles from this pulsar indicate that it can be the source of the observed peak, if the particles were confined within the SNR during a considerable fraction of its total age. We also estimate the contribution of Geminga and Vela pulsars to cosmic rays at the knee.