Detection of a new methylamine (CH3NH2) source: Candidate for future glycine surveys

Interstellar glycine (NH₂CH₂COOH), the simplest amino acid, has long been sought in studying a possible relation between the Universe and origin of life. In the last 40 or so years all surveys of glycine have failed; an alternative strategy would be to search for precursor(s) to glycine. Such studies of precursors would be crucial prior to conducting sensitive surveys with ALMA. Laboratory studies have suggested that CH₃NH₂ is a possible precursor to glycine. Further theoretical study also suggests that the CH₂NH₂ radical that can be formed from CH₃NH₂ through photodissociation can be a good precursor to glycine. Thus, we have looked for CH₃NH₂ towards several hot core sources using the Nobeyama 45 m radio telescope, and succeeded in finding a new CH₃NH₂ source, G10.47+0.03, with a fractional abundance of 1.5 ± 1.1 × 10^-8; at the time of writing, this source is the most abundant source of CH₃NH₂ ever known. We found that the observed abundance of CH₃NH₂ agrees fairly well with the theoretical value predicted by R. T. Garrod (2013, ApJ, 765, 60). The detectability of interstellar glycine is discussed.