Evolutionary Status of Long-Period Radio Pulsars

TL;DR

This paper investigates the evolutionary stages of long-period radio pulsars, suggesting that most with standard magnetic fields are unlikely to be ejectors, and discusses the conditions under which certain long-period pulsars can exist.

Contribution

It provides a detailed analysis of the evolutionary status of long-period pulsars, challenging previous assumptions about their magnetic fields and ejector stages.

Findings

PSR J0901-4046 may be at the ejector stage with realistic interstellar medium parameters.

Long-period pulsars with periods over 1000 s require unrealistically large magnetic fields to be ejectors.

Standard magnetic field neutron stars with ~100 s periods cannot be ejectors in typical interstellar medium.

Abstract

We analyze the evolutionary status of recently discovered long-period radio sources PSR J0901-4046, GLEAM-X J1627-52, and GPM J1839-10. We discuss the hypothesis that all three sources are radio pulsars. In the framework of standard scenarios, it is often accepted that the pulsar mechanism is switched off when an external matter can penetrate the light cylinder. If the matter is stopped outside the light cylinder then the neutron star is at the ejector stage. We demonstrate that for realistic parameters of the interstellar medium, the 76-second pulsar PSR J0901-4046 might be at this stage. However, sources GLEAM-X J1627-52 and GPM J1839-10 with periods $\gtrsim 1000$ s can be ejectors only in the case of unrealistically large dipolar fields $\gtrsim 10^{16}$ G. Also, we show that neutron stars with spin periods $\sim 100$ s and dipolar magnetic fields $\lesssim 10^{13}$ G cannot be ejectors in a typical interstellar medium. Thus, we predict that long-period pulsars with standard fields will not be discovered.