Search for TeV emission from spider millisecond pulsars with HAWC

TL;DR

This study uses 2565 days of HAWC data to search for very-high-energy gamma-ray emission from spider millisecond pulsars, setting upper limits and comparing redback and black widow systems.

Contribution

First comprehensive search for TeV emission from spider MSPs using HAWC data, including individual and stacked analyses to constrain their gamma-ray output.

Findings

No significant TeV emission detected from individual spider MSPs.

Stacking analysis shows no spectral differences between redback and black widow systems.

Results suggest MSPs are unlikely major contributors to Galactic TeV diffuse emission.

Abstract

Millisecond pulsars (MSPs) are observed to emit multi-wavelength radiation, from radio to GeV. Spider MSPs, which interact with their low-mass companion in close orbit (orbital periods $< 1$ day), may lead to strong intrabinary shocks that can further accelerate electron and positron pairs produced in the magnetosphere, possibly emitting very-high-energy (0.1--100 TeV; VHE) photons through inverse Compton scattering. Using 2565 days of HAWC Pass 5 data, we search for VHE emission from spider MSPs and present upper limits on individual sources. We also perform a stacking analysis to examine whether the two sets of spider systems, classified as redbacks and black widows depending on the companion mass, exhibit different spectral properties. Our study places constraints on TeV emission from MSPs and suggests that they are unlikely to contribute significantly to the Galactic diffuse emission at TeV and higher energies.