Radio Detections of Stellar Winds from the Pistol Star and Other Stars in the Galactic Center Quintuplet Cluster

Very Large Array images of the Sickle and Pistol H II regions near the Galactic center at 8.3 and 4.9 GHz reveal six point sources in the region where the dense Quintuplet stellar cluster is located. The spectral indices of five of these sources between 6 and 3.6 cm have values of α = 0.5 to 0.8 (where S ν ∝ ν α ), consistent with the interpretation that the radio sources correspond to ionized stellar winds of the massive stars in this cluster. The radio source associated with the Pistol star shows α = -0.4 ± 0.2, consistent with a flat or slightly nonthermal spectrum.