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

Abstract

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 B0 ∼ a few × 1012 G at the pole of the star. In the same model, XDINs are estimated to have relatively weak fields (B0 ≲ 1012 G) locating them well below the pulsar death line. From the simulations, we estimate that PSR J0726–2612 is at an age of t ∼ 5 × 104 yr, and will achieve the rotational properties of a normal radio pulsar within ∼105 yr, rather than the XDIN properties.