A multi-frequency , multi-configuration study has been made of the compact radio sources in the Galactic Center Quintuplet and Arches stellar clusters using the Very Large Array .
Ten radio sources have been detected in the Quintuplet cluster .
The majority of these radio sources have rising spectral indices and are positionally coincident with young massive stars that are known to have powerful stellar winds .
We conclude that the three most compact of these sources are produced by stellar wind emission ; thus , mass-loss rates can be derived and have an average value of 3 \times 10 ^ { -5 } M _ { \sun } yr ^ { -1 } .
The remainder of the sources are likely to be a combination of stellar wind emission and free-free emission from surrounding ionized gas .
In three cases , the radio sources have no stellar counterpart and the radio emission is thought to arise from compact or ultra-compact H ii regions .
If so , these sources would be the first detections of embedded massive stars to be discovered in the Galactic center clusters .
The radio nebula associated with the Pistol star resembles the nebula surrounding the LBV star \eta Carina and may be related to the stellar wind of the Pistol star .
Ten compact radio sources are detected in the Arches cluster and are interpreted to be stellar wind sources , consistent with previous findings .
Several of the sources show moderate variability ( 10-30 % ) in their flux density , possibly related to a nonthermal component in the wind emission .
A number of radio sources in both clusters have X-ray counterparts , which have been interpreted to be the shocked , colliding winds of massive binary systems .