Pulsar interpretation of the lepton spectra measured by AMS-02

TL;DR

This paper investigates whether nearby pulsars can explain the high-energy positron fraction measured by AMS-02, finding that specific pulsars can individually or collectively account for the observed spectra.

Contribution

It demonstrates that certain nearby pulsars can explain AMS-02 positron data, highlighting their potential as primary sources of high-energy positrons.

Findings

Four pulsars can individually explain the high-energy positron fraction.

Multiple pulsars may produce structures in the positron spectrum at higher energies.

Pulsars with specific age and distance ranges are consistent with AMS-02 observations.

Abstract

AMS-02 recently published its lepton spectra measurement. The results show that the positron fraction no longer increases above $\sim$200 GeV. The aim of this work is to investigate the possibility that the excess of positron fraction is due to pulsars. Nearby known pulsars from ATNF catalogue are considered as a possible primary positron source of the high energy positrons. We find that the pulsars with age $T\simeq (0.45\sim4.5)\times10^{5}$ yr and distance $d<0.5$ kpc can explain the behavior of positron fraction of AMS-02 in the range of high energy. We show that each of the four pulsars --- Geminga, J1741-2054, Monogem and J0942-5552 --- is able to be a single source satisfying all considered physical requirements. We also discuss the possibility that these high energy $e^{\pm}$ are from multiple pulsars. The multiple pulsars contribution predicts a positron fraction with some structures at higher energies.