Braking PSR J1734-3333 with a possible fall-back disk

TL;DR

This paper proposes that the pulsar PSR J1734-3333 is surrounded by a fall-back disk influencing its braking behavior, explaining its small braking index and evolutionary path.

Contribution

It introduces a modified braking torque model involving a fall-back disk to explain the pulsar's small braking index and evolutionary trajectory.

Findings

A self-similar fall-back disk can fit observed pulsar parameters.

The pulsar may evolve into an anomalous X-ray pulsar or soft gamma repeater.

Disk mass estimated around 10 Earth masses, similar to observed disks.

Abstract

The very small braking index of PSR J1734-3333, $n=0.9\pm0.2$, challenges the current theories of braking mechanisms in pulsars. We present a possible interpretation that this pulsar is surrounded by a fall-back disk and braked by it. A modified braking torque is proposed based on the competition between the magnetic energy density of a pulsar and the kinetic energy density of a fall-back disk. With this torque, a self-similar disk can fit all the observed parameters of PSR J1734-3333 with natural initial parameters. In this regime, the star will evolve to the region having anomalous X-ray pulsars and soft gamma repeaters in the $P-\dot{P}$ diagram in about 20000 years and stay there for a very long time. The mass of the disk around PSR J1734-3333 in our model is about $10M_{\oplus}$, similar to the observed mass of the disk around AXP 4U 0142+61.