CHRIS CLEMENS, UNIVERSITY OF NORTH CAROLINA

PRINCETON ASTRONOMY COLLOQUIUM - MARCH 23, 2004

ABSTRACT

Non-Radial Pulsations in Radio Pulsars

The pulsed radio emission from pulsars exhibits a variety of morphological characteristics including stationary and drifting substructure within pulses, “mode changes” that abruptly alter the character of this substructure, and pulse “nulling”, during which the pulse emission drops below detectable levels for one or more spins of the pulsar. In this talk I will exhume 30-year-old evidence, link it to recent discoveries, and re-open the case for non-radial pulsations as the culprit behind all of this
behavior. I will introduce a new model with non-radial oscillations of high spherical degree aligned to the magnetic axis of a spinning neutron star and describe quantitative tests of this model currently underway. I will also speculate about the physical nature of the proposed pulsations. The proceedings will be more “preliminary hearing” than final trial, and expert
witnesses may be called upon to testify.