Timescales of Radio Emission in Pulsar J0437−4715 at 327 MHz

Abstract

Timescales of radio emission are studied in PSR J0437-4715 at 327 MHz using almost half a million periods of high-quality data from the Ooty Radio Telescope. The radio emission in this millisecond pulsar occurs on a short (s) timescale of ≈0.026 ± 0.001 periods and on a long (l) timescale that is much longer than the widths of the components of the integrated profile (≈0.05 periods). The width of the s emission increases with its increasing relative contribution to the total radio emission. This may provide constraints on the details of discharge of vacuum gaps above pulsar polar caps. The s emission occasionally takes place in the form of intense spikes, which are confined to the main component of the integrated profile for 90% of the time. The positions of spikes within a component of the integrated profile have no simple relation to the shape of that component. This may have an impact on the interpretation of the integrated profile components in terms of independent regions of emission on the polar cap.