We present a study of signatures of on-going star formation in a sample of protostellar objects with enhanced 4.5 \mu m emission ( ‘ green ’ sources ) near the Galactic center .
To understand how star formation in the Galactic center region compares to that of the Galactic disk , we used the Expanded Very Large Array to observe radiatively excited Class II 6.7 GHz CH _ { 3 } OH masers and collisionally excited Class I 44 GHz CH _ { 3 } OH masers , both tracers of high-mass star formation , toward a sample of 34 Galactic center and foreground ‘ green ’ sources .
We find that 33 \pm 15 % of Galactic center sources are coincident with 6.7 GHz masers , and that 44 \pm 17 % of foreground sources are coincident with 6.7 GHz masers .
For 44 GHz masers , we find correlation rates of 27 \pm 13 % and 25 \pm 13 % for Galactic center green sources and foreground green sources , respectively .
Based on these CH _ { 3 } OH maser detection rates , as well as correlations of green sources with other tracers of star formation , such as 24 \mu m emission and infrared dark clouds ( IRDCs ) , we find no significant difference between the green sources in the Galactic center and those foreground to it .
This suggests that once the star formation process has begun , the environmental differences between the Galactic center region and the Galactic disk have little effect on its observational signatures .
We do find , however , some evidence that may support a recent episode of star formation in the Galactic center region .