Growth of magnetic fields in accreting millisecond pulsars

TL;DR

This paper explores how internal magnetic field growth driven by r-modes in accreting millisecond pulsars influences their external magnetic fields and spin-down evolution, offering explanations for observed pulsar behaviors.

Contribution

It introduces a new evolutionary pathway for MSPs based on magnetic field diffusion caused by r-modes, linking internal dynamics to observable spin-down rates.

Findings

Internal magnetic fields can grow significantly due to r-modes.

Magnetic field diffusion affects the spin-down rates of MSPs.

The model explains high spin-down rates in specific pulsars.

Abstract

R-modes can generate strong magnetic fields in the core of accreting millisecond neutron stars (NSs). The diffusion of these fields outside the core causes the growth of the external magnetic field and thus it affects the evolution of the spin down rates $\dot{P}$ of the millisecond pulsars (MSPs). The diffusion of the internal magnetic field provides a new evolutionary path for the MSPs. This scenario could explain the large $\dot{P}$ of the pulsars J1823-3021A and J1824-2452A.