Dr Russell Edwards (ATNF)

Probing Pulsar Magnetosphere Dynamics with Drifting Subpulses - Dr Russell Edwards Colloquium

ATNF Marsfield Lecture Theatre

Abstract

Pulses from pulsars usually include substructure, which sometimes takes
the peculiar form of a sequence of "subpulses" that, with each
successive pulse period, systematically "drift" in phase relative to
the overall pulse window. Drifting subpulse patterns provide
tantalising hints about the origin of pulsar radiation, and are
frequently taken as proof for one particular empirical model. This
model is seeing increasing use for the inference of the configuration
of the emitting region, and is even used to invert observation data to
produce a time-resolved two-dimensional map of the polar cap excitation
pattern. I will show that this model makes strong, testable predictions
concerning the shape of the drift patterns, which are demonstrably
incompatible with analyses of actual data made so far. I will also
discuss polarimetric observations of periodic drifting subpulse
patterns that reveal extraordinarily complex behaviour that strongly
implicates magnetospheric propagation effects in the production of
polarization and drifting subpulse patterns.