Abstract

About a couple of tens galactic X-ray sources display regular pulses, with periods in a range of 500-20000s. They are identified with massive close binaries in which a magnetized neutron star accretes material onto its surface. The observed pulsations are unambiguously associated with the spin period of the neutron star. Analysis of the observed spin-evolution and possible history of these pulsars in terms of currently adopted spin-down model suggests that the field strength of the neutron star exceeds the quantum critical level and hence these objects are magnetars. If this finding were correct a major revision of the magneto-rotational evolution model would be required. In my talk I show, however, that the observed behavior of the pulsars can reflect a more complicated structure of the accretion flow surrounding their magnetospheres. A solution we get in this case is consistent with currently used evolution model of close binaries.