Pulsar Bow Shocks as Probes of Warm Neutral Gas

Abstract

Pulsars have mean space velocities >~500 km/s. Theconsequent ram pressure results in tight confinement of the star'senergetic wind, driving a bow shock into the surrounding medium.Pulsar bow shocks have long been regarded as a curiosity, but newoptical and X-ray observations are both rapidly expanding the sample ofsuch sources, and are offering new ways to probe the interactionbetween pulsars and their environments. Here we discuss some of thesenew results, and explain how these data can be used to probe thedensity and structure of neutral gas in the interstellar medium.