Distance to the Pulsar B1642–03 and the Influence of the H II Region S27 on Its Dispersion Measure and Scattering Parameters

Resumo

Based on data on the dispersion measure and the interstellar-scattering parameters of the pulsar B1642–03, which is observed in the direction of the emission nebula S27 around the early-type star ζ Oph, it is concluded that this nebula makes a relatively small contribution to its dispersion measure (∼9−23%) and scattering angle (∼9−16%). It is shown that the distance to B1642–03 is 2.2–2.6 kpc.