Interstellar glycine

Yi Jehng Kuan*, Steven B. Charnley, Hui Chun Huang, Wei Ling Tseng, Zbigniew Kisiel

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

347 Citations (Scopus)


We have searched for interstellar conformer I glycine (NH 2CH2COOH), the simplest amino acid, in the hot molecular cores Sgr B2(N-LMH), Orion KL, and W51 el/e2. An improved search strategy for intrinsically weak molecular lines, involving multisource observations, has been developed and implemented. In total, 82 spectral frequency bands, in the millimeter-wave region, were observed over a 4 yr period; 27 glycine lines were detected in 19 different spectral bands in one or more sources. The rotational temperatures derived from "rotation diagrams" are 75 -16+29 K for Sgr B2(N-LMH), 141-37 +76 K for Orion KL, and 121-32+71 K for W51 el/e2. The total column densities inferred are 4.16-1.82 +3.22 × 1014 cm-2 for Sgr B2, 4.37 -1.27+1.79 × 1014 cm-2 for Orion, and 2.09-0.77+1.22 × 1014 cm -2 for W51. Production of interstellar glycine by both gas-phase ion-molecule reactions and by ultraviolet photolysis of molecular ices is briefly discussed. The discovery of interstellar glycine strengthens the thesis that interstellar organic molecules could have played a pivotal role in the prebiotic chemistry of the early Earth.

Original languageEnglish
Pages (from-to)848-867
Number of pages20
JournalAstrophysical Journal
Issue number2 I
Publication statusPublished - 2003 Aug 20


  • Astrobiology
  • ISM: abundances
  • ISM: individual (Orion Kleinmann-Low, Sagittarius B2(N-LMH), W51 el/e2)
  • ISM: molecules
  • Line: identification
  • Radio lines: ISM

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science


Dive into the research topics of 'Interstellar glycine'. Together they form a unique fingerprint.

Cite this