Multi-wavelength maser observations of the Extended Green Object G19.01—0.03

Abstract We report the detections of NH₃(3,3) and 25 GHz and 278.3 GHz class I CH₃OH maser emission associated with the outflow of the Extended Green Object G19.01–0.03 in sub-arcsecond resolution Atacama Large Millimeter/submillimeter Array (ALMA) and Karl G. Jansky Very Large Array (VLA) observations. For masers associated with the outer outflow lobes (> 12.5 ″ from the central massive young stellar object; MYSO), the spatial distribution of the NH₃(3,3) masers is statistically indistinguishable from that of previously known 44 GHz Class I CH₃OH masers, strengthening the connection of NH₃(3,3) masers to outflow shocks. In sub-arcsecond resolution VLA observations, we resolve the 6.7 GHz Class II CH₃OH maser emission towards the MYSO into a partial, inclined ring, with a velocity gradient consistent with the rotationally supported circumstellar disc traced by thermal gas emission.