Evolution of the long-period pulsar PSR J0901-4046

The fallback disc model predicted that anomalous X-ray pulsars (AXPs) and soft gamma repeaters (SGRs) will evolve to isolated long-period pulsars (LPPs) before the discovery of the first two LPPs this year. Unlike normal radio pulsars, LPPs show transient pulsed-radio epochs with unusual and variable pulse shapes, similar to the radio behaviour of the few radio emitting AXP/SGRs. We show that the present properties of the recently discovered second LPP, PSR J0901-4046 (P similar or equal to 76 s), are obtained as a result of evolution in interaction with a fallback disc, as we had already shown for the first discovered LPP, GLEAM-X J162759.5-523504.3 (P similar or equal to 1091 s). While there is only an upper limit to the period derivative, P, of GLEAM-X J162759.5-523504.3, the P of the PSR J0901-4046 has already been measured, providing better constraints for the evolutionary models. The model can produce the source properties with a dipole moment mu similar or equal to 10(30) G cm(3). The results are not sensitive to the initial pulsar period. Our results indicate that PSR J0901-4046 went through an AXP/SGR epoch at an age of a few 10(4) yr, and is similar to(6-8) x10(5) yr old at present.