2023MNRAS.525.2229M

Glycolaldehyde (CH₂OHCHO) is the simplest monosaccharide sugar in the interstellar medium, and it is directly involved in the origin of life via the 'RNA world' hypothesis. We present the first detection of CH₂OHCHO towards the hot molecular core G358.93-0.03 MM1 using the Atacama Large Millimetre/Submillimetre Array (ALMA). The calculated column density of CH₂OHCHO towards G358.93-0.03 MM1 is (1.52 ± 0.9) × 10¹⁶ cm^–2 with an excitation temperature of 300 ± 68.5 K. The derived fractional abundance of CH₂OHCHO with respect to H₂ is (4.90 ± 2.92) × 10^–9, which is consistent with that estimated by existing two-phase warm-up chemical models. We discuss the possible formation pathways of CH₂OHCHO within the context of hot molecular cores and hot corinos and find that CH₂OHCHO is likely formed via the reactions of radical HCO and radical CH₂OH on the grain-surface of G358.93-0.03 MM1.