Detection of NH<SUB>3</SUB> Molecules in the Interstellar Medium by Their Microwave Emission

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• Rank, D. M.
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• Townes, C. H.
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• Thornton, D. D.
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• Welch, W. J.

Abstract

Ammonia has been found in the direction of the galactic center by detection of its J=1, K=1 inversion transition. The region of emission closely corresponds to the position, velocity, and size of strong OH absorption. Collisional and radiative excitation mechanisms are discussed. The column density of NH₃ and the kinetic temperature of the interstellar gas cloud are estimated to be 2×10¹⁶/cm² and 23°K, respectively.