Nature of anomalous X-ray pulsars, soft gamma repeaters and radio pulsars with very long periods

Abstract

A brief review of the known models for the description of anomalous X-ray pulsars (AXPs) and soft gamma repeaters (SGRs) is given. A new model is proposed to explain the main properties of these objects on the basis of the concept of drift waves in the vicinity of the light cylinder of the neutron star with a surface magnetic field of about 1012 G. In the framework of this model, the rotation periods P, their derivatives d P/d t and the magnetic fields B in the regions of generation of emission observed in AXPs and SGRs are calculated. The intervals for these parameters are P = 11 − 737 ms, d P/d t = 3.7 × 10− 16 − 5.5 × 10− 12 and log B = 2.63 − 6.25. A modulation with periods P could be observed in the sources under consideration. The magnetic fields at the neutron star's surface calculated in the framework of the dipole model for AXPs and SGRs have the same order (⟨log B s⟩ = 11.90) as for normal radio pulsars. Pulsars of the types under consideration must have short periods (P ≈ 0.1 s) and a small ang...