Implication of the striped pulsar wind model for gamma-ray binaries

TL;DR

This paper explores how the striped pulsar wind model can explain gamma-ray emissions in binary systems, specifically analyzing PSR B1259-63's spectral variability and light curves based on its orbital and rotational phases.

Contribution

It extends the striped pulsar wind model to gamma-ray binaries, providing detailed predictions for spectral variability and light curves of PSR B1259-63.

Findings

Predicted phase-resolved gamma-ray spectra and light curves for PSR B1259-63.

Showed the striped wind model can account for observed gamma-ray emissions.

Identified orbital geometry effects on gamma-ray emission patterns.

Abstract

(abridged) Gamma-ray binaries are massive stars with compact object companions that are observed to emit most of their energy in the gamma-ray range. One of these binaries is known to contain a radio pulsar, PSR B1259-63. Synchrotron and inverse Compton emission from particles accelerated beyond the light cylinder in striped pulsar winds has been proposed to explain the X-ray to high energy (HE, $>$ 100 MeV) gamma-ray emission from isolated pulsars. This pulsar model extends naturally to binary environments, where seed photons for inverse Compton scattering are provided by the companion star. Here, we investigate the possibility of gamma-ray emission from PSR B1259-63 in the framework of the striped pulsar wind model. The orbital geometry of PSR B1259-63 is well constrained by observations and the double radio pulse suggests an almost orthogonal rotator so that the solid angle covered by the striped region is close to $4\pi$. We calculate the orbital and rotational phase-resolved spectral variability and light-curves to expect.