Diagnosing Interstellar Magnetic Turbulence with TeV Pulsar Halos

TL;DR

This paper proposes using the morphology of TeV pulsar halos as a new method to diagnose interstellar magnetic field properties, based on anisotropic diffusion models and X-ray observations.

Contribution

It introduces a theoretical framework linking pulsar halo morphology to interstellar magnetic field parameters, enhancing magnetic field diagnostics.

Findings

Established a relation between halo morphology and magnetic field properties.

Demonstrated how X-ray data can improve magnetic field diagnosis.

Proposed a novel observational approach using pulsar halos.

Abstract

Interstellar magnetic field is essential in various astrophysical phenomena and processes. Pulsar halos are a recently discovered class of TeV gamma-ray sources formed by escaping electrons/positrons from pulsars. The morphology of the halo is regulated by the diffusion of those escaping particles, and hence carries information of the interstellar magnetic field. We suggest that the morphology of TeV pulsar halos can be used as a novel probe of the properties of interstellar magnetic field around the pulsar, such as the Alfv\'{e}nic Mach number and the mean direction. We establish a theoretical relation between these quantities and the observational features of the halo's morphology based on the anisotropic diffusion model, and show how X-ray observations of the pulsar halos can further improve the diagnosis of the magnetic field.