Evolutionary Status of Long-Period Radio Pulsars

We consider the evolutionary status of the recently discovered long-period radio sources PSR J0901-4046, GLEAM-X J1627-52, and GPM J1839-10. It is hypothesized that all three sources are radio pulsars. Within the framework of standard scenarios, it is thought that for the pulsar mechanism to operate, it is necessary to exclude the penetration of external matter into the light cylinder, which corresponds to the ejector stage. We show that for realistic properties of the interstellar medium the 76-second pulsar J0901-4046 must be at this stage, whereas the sources GLEAM-X J1627-52 and GPM J1839-10 with periods \({\gtrsim}1000\) s can be at this stage only in the case of unrealistically high dipolar magnetic fields \({\gtrsim}10^{16}\) G. We also show that sources with periods \({\sim}100\) s and magnetic fields \({\lesssim}10^{13}\) G cannot be ejectors in a realistic interstellar medium. Thus, we predict that long-period radio pulsars with standard magnetic fields will not be discovered.