Environments of Supernova Remnants Which Contain Different Types of Neutron Star

Abstract

In the last few years new types of neutron stars having various degrees of activity have been identified. Among these are there dim radio quiet neutron stars and anomalous X-ray pulsars. In order to get some information about masses of progenitors of these neutron stars as well as about masses of progenitors of radio pulsars and single strong X-ray pulsars, we have examined environments of the supernova remnants connected to these neutron stars and pulsars. We have approached the problem through 4 independent ways: we have examined surface brightness – radius, surface brightness – age, and radius – age graphs of the supernova remnants as well as the observational data about the densities in the shock fronts and in the ambient media of the supernova remnants. We have also examined the environments of C- and S-type supernova remnants in which no point source has been observed. Densities of the ambient media of the supernova remnants connected to these different types of neutron stars are not very different from each other that there seems to be no reliable relation between mass of the progenitor star and the degree of activity or passivity of the neutron star. The S-type supernova remnants without point sources are expanding in less dense media that their progenitors might be less massive stars compared to the progenitors of the neutron stars and pulsars mentioned above.