Line integrals of N[SUB]E[/SUB] and (n[SUB]E)-squared[/SUB] at high Galactic latitude

Abstract

Recent discoveries of pulsars in high-absolute-z globular clusters have made it possible for the first time to compare unambiguously the value of integral of n<SUB>e</SUB> ds with the value of integral of (n<SUB>e)-squared</SUB> ds along four 'random' lines of sight at high absolute value of b. The results imply that the diffuse interstellar H(+) is clumped into regions which have an average electron density 0.08/cu cm and which occupy a fraction f equal to or greater than 0.2 of the volume within a 2 kpc thick H(+) layer. The similarity of the results for each of the widely separated directions suggests that there is little variation in the properties of the gas within the solar neighborhood. There is some evidence that the filling fraction increases with distance away from the Galactic midplane.