Identification of the simplest sugar-like molecule glycolaldehyde towards the hot molecular core G358.93-0.03 MM1

TL;DR

This paper reports the first detection of glycolaldehyde, a sugar-like molecule, in a hot molecular core using ALMA, providing insights into its abundance, formation pathways, and implications for the origin of life.

Contribution

It presents the first observational detection of glycolaldehyde in G358.93-0.03 MM1 and discusses its formation mechanisms in hot molecular cores.

Findings

Glycolaldehyde detected with a column density of (1.52±0.9)×10^{16} cm^{-2}

Fractional abundance of glycolaldehyde is (4.90±2.92)×10^{-9}

Likely formation via radical reactions on grain surfaces

Abstract

Glycolaldehyde (CH$_{2}$OHCHO) 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 glycolaldehyde (CH$_{2}$OHCHO) towards the hot molecular core G358.93-0.03 MM1 using the Atacama Large Millimeter/Submillimeter Array (ALMA). The calculated column density of CH$_{2}$OHCHO towards G358.93-0.03 MM1 is (1.52$\pm$0.9)$\times$10$^{16}$ cm$^{-2}$ with an excitation temperature of 300$\pm$68.5 K. The derived fractional abundance of CH$_{2}$OHCHO with respect to H$_{2}$ is (4.90$\pm$2.92)$\times$10$^{-9}$, which is consistent with that estimated by existing two-phase warm-up chemical models. We discuss the possible formation pathways of CH$_{2}$OHCHO within the context of hot molecular cores and hot corinos and find that CH$_{2}$OHCHO is likely formed via the reactions of radical HCO and radical CH$_{2}$OH on the grain surface of G358.93-0.03 MM1.