Gamma-rays from the binary system containing PSR J2032+4127 during its periastron passage

TL;DR

This paper models gamma-ray emission during the periastron passage of the PSR J2032+4127 binary system, predicting conditions under which binary emission exceeds background TeV gamma-ray levels.

Contribution

It introduces a simple geometrical model to calculate gamma-ray spectra from pulsar-stellar wind interactions during periastron.

Findings

Gamma-ray emission can surpass steady TeV background during periastron.

Conditions for detectable binary gamma-ray signals are identified.

Model predictions align with observed TeV gamma-ray spectra.

Abstract

The energetic pulsar, PSR J2032+4127, has been recently discovered in the direction of the unidentified HEGRA TeV gamma-ray source (TeV J2032+4130). It is proposed that this pulsar forms a binary system with the Be type star, MT91 213, expected to reach the periastron late in 2017. We performed detailed calculations of the gamma-ray emission produced close to the binary system's periastron passage by applying a simple geometrical model. Electrons accelerated at the collision region of pulsar and stellar winds initiate anisotropic Inverse Compton electron-positron pair cascades by scattering soft radiation from the massive companion. The gamma-ray spectra, from such a comptonization process, are confronted with the measurements of the extended TeV gamma-ray emission from the HEGRA TeV gamma-ray source. We discuss conditions within the binary system, at the periastron passage of the pulsar, for which the gamma-ray emission from the binary can overcome the extended, steady TeV gamma-ray emission from the HEGRA TeV gamma-ray source.