Detectability of Glycine in Solar-type System Precursors

Abstract

Glycine (NH2CH2COOH) is the simplest amino acid relevant for life. Its detection in the interstellar medium is key to understand the formation mechanisms of pre-biotic molecules and their subsequent delivery onto planetary systems. Glycine has extensively been searched for toward hot molecular cores, although these studies did not yield any firm detection. In contrast to hot cores, low-mass star forming regions, and in particular their earliest stages represented by cold pre-stellar cores, may be better suited for the detection of glycine as well as more relevant for the study of pre-biotic chemistry in young Solar System analogs. We present 1D spherically symmetric radiative transfer calculations of the glycine emission expected to arise from the low-mass pre-stellar core L1544. Water vapour has recently been reported toward this core, indicating that a small fraction of the grain mantles in L1544 (~0.5%) has been injected into the gas phase. Assuming that glycine is photo-desorbed together with water in L1544, and considering a solid abundance of glycine on ices of ~1E-4 with respect to water, our calculations reveal that several glycine lines between 67 GHz and 80 GHz have peak intensities larger than 10 mK. These results show for the first time that glycine could reach detectable levels in cold objects such as L1544. This opens up the possibility to detect glycine, and other pre-biotic species, at the coldest and earliest stages in the formation of Solar-type systems with near-future instrumentation such as the Band 2 receivers of ALMA.

5 pages, 2 figures, 1 tables. Accepted for publication in ApJ Letters

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Cited by in corpus (11)

• The Spatial Distribution of Complex Organic Molecules in the L1544 Pre-stellar Core
• A non-energetic mechanism for glycine formation in the interstellar medium
• The formation of the solar system
• Formation of hydroxylamine on dust grains via ammonia oxidation
• Millimetre-wave laboratory study of glycinamide and search for it with ALMA toward Sagittarius B2(N)
• Deep Search for Glycine Conformers in Barnard 5
• Detection of possible glycine precursor molecule methylamine towards the hot molecular core G358.93$-$0.03 MM1
• Astrochemical effect of the fundamental grain surface processes I. The diffusion of grain surface species and the pre-exponential factor
• Investigating the impact of reactions of C and CH with molecular hydrogen on a glycine gas-grain network
• The SKA as a prebiotic molecule detector
• CAB: Towards the RNA-world in the interstellar medium -- detection of urea, and search of 2-amino-oxazole and simple sugars