Disclosing the catalog pulsars dominating the Galactic positron flux

TL;DR

This paper models the contribution of known pulsars to the Galactic positron flux observed by AMS-02, identifying key sources that dominate high-energy positron emission and suggesting targeted follow-up observations.

Contribution

It demonstrates that a small number of nearby pulsars can account for most of the high-energy positron flux, integrating catalog data with emission modeling.

Findings

Nearby pulsars like Geminga and Monogem dominate positron flux above 100 GeV.

Model fits suggest pulsars can explain the observed positron excess.

Multi-wavelength follow-up is recommended to refine source contributions.

Abstract

The cosmic-ray flux of positrons is measured with high precision by the space-borne particle spectrometer AMS-02. The hypothesis that pulsars and their nebulae can significantly contribute to the excess of the AMS-02 positron flux has been consolidated after the observation of a $\gamma$-ray emission at GeV and TeV energies of a few degree size around a few sources, that provide indirect evidence that electron and positron pairs are accelerated to very high energies from these sources. By modeling the emission from pulsars in the ATNF catalog, we find that combinations of positron emission from cataloged pulsars and secondary production can fit the observed AMS-02 data. Our results show that a small number of nearby, middle-aged pulsars, particularly B1055-52, Geminga (J0633+1746), and Monogem (B0656+14), dominate the positron emission, contributing up to 80\% of the flux at energies above 100 GeV. From the fit to the data, we obtain a list of the most important sources for which we recommend multi-wavelength follow-up observations, particularly in the $\gamma$-ray and X-ray bands, to further constrain the injection and diffusion properties of positrons.