THE DENSE MOLECULAR ENVELOPE AROUND THE COMPACT-H-II REGION-G5.89-0.39 (W28 A2)

We present VLA observations of ammonia in the (J, K) = (2, 2) and (3, 3) inversion transitions toward the compact H II region G5.89-0.39. These observations reveal the presence of a massive (approximately 30 M. and hot (approximately 90 K) molecular envelope that is clumpy and probably undergoing expansion. We also detect overheated or inverted (3, 3) ammonia emission in front of the H II region. The radio continuum map shows bipolar protuberances, suggesting that the ionized gas is flowing out through openings in the molecular envelope.