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).
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