Pulsar distances, spiral structure and the interstellar medium

Abstract

The distances of all pulsars are calculated on the assumption that they are immersed in a uniform medium of average electron density 0.06 cm⁻³. It then appears that the pulsars are concentrated towards the local and Sagittarius spiral features and that their mean height above the plane is consistent with that of known supernova remnants. The mean distances appear to be approximately correct, but individual distances are uncertain by about a factor of two. Evidence from radio continuum results supports this model of the ionized interstellar medium.