4.7GHz OH masers in northern star formation regions

One source (G005.885-0.392) was first detected with quasi-thermal emission at 4660MHz. We have investigated the associations between the detected 4.7GHz OH masers with ground-state OH masers near 1.7GHz, 6.7GHz methanol masers and 22GHz water masers reported in the literature. We find that the presence of 1665MHz OH masers is a better indicator of the presence of 4.7GHz OH masers than 1720MHz OH masers.

The majority of the 4.7GHz OH masers are associated with 6.7GHz methanol and/or 22GHz water masers. We have compared the characteristics of our detections with those reported previously in the literature and found that only five sources are fairly stable.