Detection of a dense group of hyper-compact radio sources in the central parsec of the Galaxy

Understand

Using the JVLA, we explored the Galactic center (GC) with a resolution of 0.05" at 33.0 and 44.6 GHz.

• We detected 64 hyper-compact radio sources (HCRs) in the central parsec.
• The dense group of HCRs can be divided into three spectral types: 38 steep-spectrum ($\alpha\le-0.5$) sources; 10 flat-spectrum ($-0.5<\alpha\le0.2$) sources; and 17 inverted-spectrum sources having $\alpha>0.2$, assuming $S\propto\nu^\alpha$.
• The steep-spectrum HCRs are likely represent a population of massive stellar remnants associated with nonthermal compact radio sources powered by neutron stars and stellar black holes.