High Energy Emission from Black Widows and Redbacks

TL;DR

This paper models high-energy emissions from black widow and redback pulsar systems, predicting observable X-ray, GeV, and TeV signals modulated by orbital motion, to probe pulsar wind physics.

Contribution

It introduces a 3D emission model for black widow and redback systems, predicting high-energy signatures and their orbital modulation, advancing understanding of pulsar wind interactions.

Findings

Synchrotron X-ray emission is detected and modulated in some systems.

Model predicts potential GeV and TeV emissions detectable under certain conditions.

Relativistic shock acceleration physics can be probed through these emissions.

Abstract

A large number of new black widow and redback energetic millisecond pulsars with irradiated stellar companions have been discovered through radio searches of unidentified \emph{Fermi} sources. We construct a 3D emission model of these systems to predict the high-energy emission components from particles accelerated to several TeV in the intrabinary shocks, and its predicted modulation at the binary orbital period. Synchrotron emission is expected at X-ray energies and such modulated emission has already been detected by \emph{Chandra} and \emph{XMM-Newton} in some systems. Synchrotron and inverse Compton emission from relativistic particles in the pulsar wind and intrabinary shock can probe the unknown physics of pulsar winds and relativistic shock acceleration in these compact binaries. Orbitally-modulated emission in the GeV and TeV bands may be detectable under some favorable conditions.