Discovery of a young stellar object near the water masers in W3(OH)

Abstract

A high-resolution (1.2 arcsec) aperture synthesis map of the ultracompact H II region W3(OH) in the 88.6 GHz transition of HCN is presented. The map is based on observations carried out with the Hat Creek millimeter interferometer. An HCN emission feature was detected near the position of the H20 masers, approximately 7 arcsec west of the continuum source. The velocity of the HCN emission indicates a physical association with the masers. The luminosity and high brightness temperature of the emission, and the broad HCN line width indicate the presence of an obscured young star within the clump. An optical depth of more than 50 at 10 microns toward the source was calculated, corresponding to a visual extinction of greater than 900 mag. Due to the high mid-infrared extinction, it is suggested that the star may only be studied by high resolution molecular line observations.