New ammonia masers towards NGC 63341

Abstract

We report the detection of new ammonia masers in the non-metastable (8,6) and (11,9) transitions towards the massive star-forming region NGC6334I. Observations were made with the Australia Telescope Compact Array interferometer and the emitting region appears unresolved in the 2.7 × 0.8 arcsec2 beam, with deconvolved sizes less than an arcsecond. We estimate peak brightness temperatures of 7.8 × 105 and 1.2 × 105 K for the (8,6) and (11,9) transitions, respectively. The masers appear coincident both spatially and in velocity with a previously detected ammonia (6,6) maser. We also suggest that emission in the (10,9), (9,9) and (7,6)transitions may also be masers, based on the small linewidths and overlapping velocity ranges with the above masers, as observed with the single-dish Mopra radio telescope.