The Crab Pulsar at Centimeter Wavelengths: I. Ensemble Characteristics

TL;DR

This study provides high-resolution radio observations of the Crab Pulsar across a wide frequency range, revealing significant changes in its emission profile and pulse characteristics between low and high radio frequencies.

Contribution

It offers new high time-resolution data at centimeter wavelengths and detailed analysis of the pulsar's emission components, highlighting frequency-dependent profile changes.

Findings

Mean profile dominated by different components below and above 5 GHz.

Disappearance of the Main Pulse at high frequencies.

Distinct characteristics of high-frequency emission components.

Abstract

We have observed the pulsar in the Crab Nebula at high radio frequencies and high time resolution. We present continuously sampled data at 640-ns time resolution, and individual bright pulses recorded at down to 0.25-ns time resolution. Combining our new data with previous data from our group and from the literature shows the dramatic changes in the pulsar's radio emission between low and high radio frequencies. Below about 5 GHz the mean profile is dominated by the bright Main Pulse and Low-Frequency Interpulse. Everything changes, however, above about 5 GHz; the Main Pulse disappears, the mean profile of the Crab pulsar is dominated by the High-Frequency Interpulse (which is quite different from its low-frequency counterpart) and the two High-Frequency Components. We present detailed observational characteristics of these different components which future models of the pulsar's magnetosphere must explain.