A Bursting Radio Transient in the Direction of the Galactic Center

TL;DR

A new radio transient near the Galactic Center was discovered with rapid variability and high brightness temperature, indicating a coherent emission process, highlighting the potential of long wavelength radio observations for transient detection.

Contribution

This paper reports the discovery of a unique radio transient with unusual properties using long wavelength observations, expanding knowledge of Galactic Center phenomena.

Findings

Discovered a transient radio source GCRT J1745-3009 near the Galactic Center.

Source exhibits rapid variability and high brightness temperature, suggesting coherent emission.

Re-detections and multi-wavelength searches provide insights into its nature.

Abstract

The radio sky is poorly sampled for rapidly varying transients because of the narrow field-of-view of most imaging radio telescopes at cm and shorter wavelengths. The emergence of sensitive long wavelength observations with intrinsically larger fields-of-view are changing this situation, as partly illustrated by our ongoing meter-wavelength monitoring observations and archival studies of the Galactic Center. In this search, we discovered a transient, bursting, radio source in the direction of the Galactic Center, GCRT J1745-3009, with extremely unusual properties. Its flux and rapid variability imply a brightness temperature >10^12 K if it is at a distance >70 pc, implying that it is a coherent emitter. I will discuss the discovery of the source and the subsequent re-detections, as well as searches for counterparts at other wavelengths, and several proposed models.