On the Transition from Accretion Powered to Rotation Powered Millisecond Pulsars

TL;DR

This paper proposes a gamma-ray irradiation mechanism from pulsar magnetospheres that heats accretion disks, facilitating the transition from accretion-powered to rotation-powered millisecond pulsars, with application to PSR J1023+0038.

Contribution

It introduces a model linking gamma-ray irradiation to disk heating and the transition process, applied specifically to PSR J1023+0038.

Findings

Gamma-ray luminosity can explain disk disappearance in PSR J1023+0038.

Model accounts for optical brightness of the companion star.

Supports gamma-ray irradiation as a key factor in pulsar state transition.

Abstract

The heating associated with the deposition of $\gamma$-rays in an accretion disk is proposed as a mechanism to facilitate the transformation of a low mass X-ray binary to the radio millisecond pulsar phase. The $\gamma$-ray emission produced in the outer gap accelerator in the pulsar magnetosphere likely irradiates the surrounding disk, resulting in its heating and to the possible escape of matter from the system. We apply the model to PSR J1023+0038, which has recently been discovered as a newly born rotation powered millisecond pulsar. The predicted $\gamma$-ray luminosity $\sim 6 \times 10^{34}~\mathrm{erg~s^{-1}}$ can be sufficient to explain the disappearance of the truncated disk existing during the 8~month$\sim 2$~yr period prior to the 2002 observations of J1023+0038 and the energy input required for the anomalously bright optical emission of its companion star.