GUAPOS II. Identified transitions of molecules

In this second paper, we discuss the detection and relative abundances of the peptide-like bond molecules: HNCO, HC(O)NH2, CH_3_NCO, CH_3_C(O)NH_2_, CH_3_NHCHO, CH_3_CH_2_NCO, NH_2_C(O)NH_2_, NH_2_C(O)CN, and HOCH_2_C(O)NH_2_. Observations were carried out with the ALMA interferometer, covering all of band 3 (about 32GHz bandwidth) with an angular resolution of 1.2"x1.2" (about 4400aux4400au) and a spectral resolution of about 0.488MHz.

The transitions of the nine molecules have been analyzed with the software MADCUBA to determine the physical parameters of the emitted gas. The results suggest that all these species are formed on grain surfaces in early evolutionary stages of molecular clouds, and that they are subsequently released back to the gas-phase through thermal desorption or shock-triggered desorption.