The Emission Physics of Millisecond Pulsars

TL;DR

This paper reviews the physics of millisecond pulsars, focusing on their emission mechanisms, magnetic fields, and recent observational findings from gamma-ray and X-ray studies, highlighting their similarities to young pulsars.

Contribution

It provides a comprehensive overview of the emission physics of MSPs, integrating recent models and observations to enhance understanding of their high-energy phenomena.

Findings

MSPs have light curves similar to young pulsars in gamma-rays.

Magnetic fields at the light cylinder in MSPs are comparable to energetic pulsars.

Binary MSP systems show orbitally-modulated X-ray emissions.

Abstract

Understanding the physics of rotation-powered millisecond pulsars (MSPs) presents a number of challenges compared to that of the non-recycled pulsar population. Even though their fast rotation rates can produce high spin-down power and accelerating electric fields, their relatively low surface magnetic fields make the production of electron-positron pairs required for radio emission difficult. The Fermi Gamma-Ray Space Telescope has discovered pulsed W-rays from a large fraction of the MSP population that have light curves surprisingly similar to those of young pulsars. However, their very compact magnetospheres enable magnetic fields at the light cylinder that are comparable to those of the most energetic pulsars. This fact and recent global magnetosphere models showing that particle acceleration takes place near and beyond the light cylinder, now makes the W-rays from MSPs plausible. The large increase in binary systems harboring MSPs has revitalized the study of shock acceleration and high-energy emission in such systems, with many showing orbitally-modulated X-rays. This Chapter will review the history and our current studies of the mechanisms for multiwavelength emission from MSPs.