Short-lived Radio Bursts from the Crab Pulsar

TL;DR

This paper reports high-time-resolution observations of the Crab pulsar revealing short-lived microbursts with rapid energy and duration fluctuations, indicating intrinsic emission processes rather than propagation effects.

Contribution

It provides new high-resolution data on pulsar microbursts, demonstrating intrinsic variability and frequency-dependent burst durations, advancing understanding of pulsar radio emission mechanisms.

Findings

Microbursts vary dramatically in energy and duration within less than a millisecond.

Burst duration scales with frequency as ν^{-2}, inconsistent with interstellar scattering.

Fluctuations are intrinsic to the pulsar emission process, not caused by propagation effects.

Abstract

Our high-time-resolution observations reveal that individual main pulses from the Crab pulsar contain one or more short-lived microbursts. Both the energy and duration of bursts measured above 1 GHz can vary dramatically in less than a millisecond. These fluctuations are too rapid to be caused by propagation through turbulence in the Crab Nebula or the interstellar medium; they must be intrinsic to the radio emission process in the pulsar. The mean duration of a burst varies with frequency as $\nu^{-2}$, significantly different from the broadening caused by interstellar scattering. We compare the properties of the bursts to some simple models of microstructure in the radio emission region.