Constraining Radio Emission from Magnetars

TL;DR

This study conducted radio observations of five magnetars at 1950 MHz, finding no emission and setting the most stringent upper limits to date, which informs future searches for magnetar radio signals.

Contribution

The paper provides the most sensitive radio luminosity upper limits for magnetars at 1950 MHz, enhancing constraints on their radio emission properties.

Findings

No radio emission detected from any target.

Established the most stringent upper limits on magnetar radio luminosity.

Discussed implications for future radio observations of magnetars.

Abstract

We report on radio observations of five magnetars and two magnetar candidates carried out at 1950 MHz with the Green Bank Telescope in 2006-2007. The data from these observations were searched for periodic emission and bright single pulses. Also, monitoring observations of magnetar 4U0142+61 following its 2006 X-ray bursts were obtained. No radio emission was detected was detected for any of our targets. The non-detections allow us to place luminosity upper limits (at 1950 MHz) of approximately L < 1.60 mJy kpc^2 for periodic emission and L < 7.6 Jy kpc^2 for single pulse emission. These are the most stringent limits yet for the magnetars observed. The resulting luminosity upper limits together with previous results are discussed, as is the importance of further radio observations of radio-loud and radio-quiet magnetars.