A search for interstellar glycine

Abstract

A search has been made for the simplest amino acid — glycine — in Sgr B2, Ori A and seven other molecular clouds. Six different lines were sought ranging from 83.4 GHz down to 22.7 GHz and radiotelescopes at Parkes, New South Wales, Kitt Peak, Arizona, and Onsala, Sweden, were used. On the assumption of reasonable values for Tex and Boltzmann distributions over rotational energy states, upper limits of column densities for glycine of a few times 1012 cm−2 to a few times 1014 cm−2 were typically established in the sources surveyed. Glycine appears to be less abundant than ethanol or ethyl cyanide in molecular clouds such as Sgr B2 and Ori A.