A Population of Compact Radio Sources at the Galactic Center

TL;DR

This study used high-resolution, high-dynamic range radio imaging with JVLA to identify a population of compact radio sources in the Galactic center's radio bright zone, revealing potential high-energy objects like neutron stars and black holes.

Contribution

It presents the first high-resolution, deep radio images of the Galactic center's RBZ at 5.5 and 9 GHz, uncovering a population of compact sources and reporting new findings on the Cannonball and GCT.

Findings

Detection of compact radio sources with flux densities from a few μJy to mJy.

Identification of steep-spectrum sources as potential high-energy objects.

New observations of the Cannonball and Galactic center transient.

Abstract

The radio bright zone (RBZ) at the Galactic center has been observed with the JVLA in the A, B and C array configurations at 5.5 and 9 GHz. With a procedure for high-dynamic range imaging developed on CASA, we constructed deep images a resolution up to 0.2", achieving rms noises of a few $\mu$Jy/beam. From the high-resolution and high-dynamics range images at 5.5 and 9 GHz, a population of compact radio sources ranging from a few mJy to a few tens $\mu$Jy in flux density is revealed. The steep-spectrum radio sources in RBZ are likely the candidates of high-energy objects that are associated with neutron stars and/or stellar mass black holes at the Galactic center. We report new results of the Cannonball and Galactic center transient (GCT).