The Mechanism of Component Formation out of the Main Pulse of a Radio Pulsar. I. The Precursor

Abstract

Induced scattering of radio emission off the ultrarelativistic particles in a superstrong magnetic field is considered. The problem of radio beam scattering into the background radiation is solved. In the magnetosphere of a pulsar, this process can be efficient, and the scattered radiation concentrates close to the external magnetic field direction. Because of rotational aberration, the scattered component precedes the main pulse in the pulse profile and can be identified with the precursor component of a pulsar. Within our model, the observed polarization, spectral and fluctuation properties of the precursor emission as well as its connection to the main pulse are explained.