A Search for Single Radio Pulses and Bursts from Southern AXPs

TL;DR

This study conducted radio observations of four southern AXPs to detect potential radio emissions but found no evidence of either periodic or burst signals, suggesting a weak link between AXPs and radio transients.

Contribution

The paper revisits previous radio data of AXPs in light of recent radio activity in XTE J1810-197, providing new constraints on radio emission from these objects.

Findings

No periodic radio signals detected from the four AXPs.

No single pulses or bursts observed at various dispersion measures.

Results weaken the proposed connection between AXPs and radio transients.

Abstract

We observed four southern AXPs in 1999 near 1400 MHz with the Parkes 64-m radio telescope to search for periodic radio emission. No Fourier candidates were discovered in the initial analysis, but the recent radio activity observed for the AXP XTE J1810-197 has prompted us to revisit these data to search for single radio pulses and bursts. The data were searched for both persistent and bursting radio emission at a wide range of dispersion measures, but no detections of either kind were made. These results further weaken the proposed link between rotating radio transient sources and magnetars. However, continued radio searches of these and other AXPs at different epochs are warranted given the transient nature of the radio emission seen from XTE J1810-197, which until very recently was the only known radio-emitting AXP.