The orbital observatories PAMELA and AMS-02 have detected a significant excess in the cosmic-ray (CR) positron flux at energies above several tens of GeV. The measured values exceed those expected in models of secondary origin of positrons due to inelastic collisions of CR nuclei with the interstellar matter. This excess may be due to the annihilation or decay of hypothetical dark matter particles or, alternatively, to the contribution of local sources of primary positrons, particularly pulsars. In contrast, the antiproton fluxes observed by AMS-02 at energies above GeV are consistent with the models of their secondary origin, taking into account the uncertainties. The ratio of the observed positron flux to the antiproton flux is virtually independent of energy in the range from 60 to 400 GeV. This behavior can be understood if the observed local spectra of positrons and antiprotons in the range of tens to hundreds of GeV are formed by the same source. The relativistic winds of pulsars inject accelerated electrons and positrons into the interstellar medium. Fast-moving pulsars form pulsar wind nebulae with bow shocks (BSPWNe), which accelerate both the freshly injected positrons and electrons of the pulsar wind and the hadrons and leptons of galactic CRs from the interstellar medium via the Fermi acceleration mechanism in colliding flows. Such a system can produce identical particle spectra regardless of the site of their injection. The nearest to the Earth millisecond pulsar PSR J0437-4715 forms a pulsar wind nebula (PWN) with a bow shock observable in optical and ultraviolet wavelengths. This BSPWN is a possible candidate for the main near-Earth ‘‘factory’’ of antiparticles along with the Geminga PWN. Considering PSR J0437-4715, we provide the Monte Carlo simulations of particle acceleration in its BSPWN and the analytical model of anisotropic diffusion in the local interstellar medium. We show that this pulsar’s contribution can explain the observed positron flux in the range from 30 GeV to 1 TeV, and simultaneously the antiproton flux at hundreds of GeV with an almost energy-independent positron-to-antiproton flux ratio. The model allows to reproduce the observed antiparticle fluxes if 25\% of the PSR J0437-4715 pulsar wind power is transferred to accelerated positrons and electrons and used to re-accelerate antiprotons.
Petrov et al. (Fri,) studied this question.