Pulsar radio emission geometry

Abstract

Pulsar radio emission is belived to come from relativistic plasma accelerated along the dipolar magnetic field lines in pulsar magnetosphere. The beamed emission by relativistic sources occur in the direction of tangents to the field lines in the corotating frame, but in an inertial (lab) frame it is aberrated toward the direction of rotation. To receive such a beamed emission line-of-sight must align with the source velocity within the beaming angle 1/γ, where γ is the Lorentz factor of the source. By solving the viewing geometry, in an inclined and rotating dipole magnetic field, we find the coordinates of the emission region in corotating frame. Next, give a general expression for the phase shift in the intensity profile in lab frame by taking into account of aberration, retardation and polar cap currents.