On the Possibility of Curvature Radiation from Radio Pulsars

TL;DR

This paper critically examines the hypothesis that coherent curvature radiation explains pulsar radio emissions, concluding it is unlikely below a few GHz and at higher frequencies due to energy and observational constraints.

Contribution

The paper provides a detailed analysis ruling out coherent curvature radiation as the primary emission mechanism for pulsars across a broad frequency range.

Findings

Coherent curvature radiation cannot account for pulsar radio emissions below a few GHz.

At higher frequencies, observational data contradict the predictions of curvature radiation models.

No effective bunching mechanism for coherent curvature radiation has been identified.

Abstract

We consider the widespread hypothesis that coherent curvature radiation is responsible for the radio emission of pulsars. The comparison of energy conservation and the published data and luminosities explicitely proves that coherent curvature radiation cannot be the source for the radio emission of pulsars for frequencies below a few GHz. At higher frequencies coherent curvature radiation can be ruled out because neither the observationally deduced emission heights nor the observed radius to frequency mapping can be reproduced by this mechanism. Our argumentation is in accordance with the more general critics (e.g. Melrose 1992) that no adequate bunching mechanism has been identified for coherent curvature radiation. We present 5 examples (0329+29, 0355+54, 0540+23, 1133+16, 1916+10) of pulsars whose high frequency (larger than 1.4. GHz, up to 32 GHz) luminosities are well known, and as a low frequency example the faintest radio pulsar 0655+64 of the Taylor et al (1993) sample.