First detection of glycolaldehyde outside the Galactic Center

TL;DR

This paper reports the first detection of glycolaldehyde outside the Galactic Center, revealing its presence in a hot molecular core and supporting surface reactions as its formation pathway.

Contribution

It provides the first observational evidence of glycolaldehyde in a hot core beyond the Galactic Center and links its formation to surface reactions on grains.

Findings

Glycolaldehyde detected in G31.41+0.31 hot core.

Emission from regions >300 K and >2E8 cm^-3.

Surface reactions on grains likely form glycolaldehyde.

Abstract

Glycolaldehyde is the simplest of the monosaccharide sugars and is directly linked to the origin of life. We report on the detection of glycolaldehyde (CH2OHCHO) towards the hot molecular core G31.41+0.31 through IRAM PdBI observations at 1.4, 2.1, and 2.9 mm. The CH2OHCHO emission comes from the hottest (> 300 K) and densest (>2E8 cm^-3) region closest (< 10^4 AU) to the (proto)stars. The comparison of data with gas-grain chemical models of hot cores suggests for G31.41+0.31 an age of a few 10^5 yr. We also show that only small amounts of CO need to be processed on grains in order for existing hot core gas-grain chemical models to reproduce the observed column densities of glycolaldehyde, making surface reactions the most feasible route to its formation.