Is PSR J0726-2612 a dim isolated neutron star progenitor?

TL;DR

This study investigates whether PSR J0726-2612 could evolve into a typical radio pulsar rather than a dim isolated neutron star, using fallback disc models to simulate its long-term evolution.

Contribution

The paper applies fallback disc models to predict the evolutionary path of PSR J0726-2612, suggesting it will become a normal radio pulsar instead of an XDIN.

Findings

PSR J0726-2612's properties are consistent with high-B radio pulsars.

Estimated age of PSR J0726-2612 is around 50,000 years.

It is predicted to evolve into a normal radio pulsar within 100,000 years.

Abstract

The rotational properties and X-ray luminosity of PSR J0726-2612 are close to those of dim isolated neutron stars (XDINs). It was proposed that the source could be the first XDIN with observable pulsed radio emission. We have investigated the long-term evolution of the source to test this possibility in the fallback disc model. Reasonable model curves that can account for the evolution of PSR J0726-2612 consistently with its radio pulsar property are similar to those of high-B radio pulsars with dipole field strength $B_0 \sim$ a few $\times 10^{12}~$G at the pole of the star. In the same model, XDINs are estimated to have relatively weak fields ($B_0 \lesssim 10^{12}~$G) locating them well below the pulsar death line. From the simulations, we estimate that PSR J0726-2612 is at an age of $t \sim 5 \times 10^4~$yr, and will achieve the rotational properties of a normal radio pulsar within $\sim 10^5~$yr, rather than the XDIN properties.