Complex organic molecules in comets C/2012 F6 (Lemmon) and C/2013 R1 (Lovejoy): detection of ethylene glycol and formamide

TL;DR

This study detected complex organic molecules, including ethylene glycol and formamide, in two comets, revealing their abundances and suggesting the presence of prebiotic compounds in cometary material.

Contribution

First detection of ethylene glycol and formamide in comets C/2012 F6 and C/2013 R1, expanding knowledge of complex organics in cometary environments.

Findings

Ethylene glycol and formamide abundances are 0.2-0.3% and 0.02% relative to water.

Detected additional molecules HCOOH and CH3CHO in comet Lovejoy.

Abundance levels are similar to those in comet Hale-Bopp.

Abstract

A spectral survey in the 1 mm wavelength range was undertaken in the long-period comets C/2012 F6 (Lemmon) and C/2013 R1 (Lovejoy) using the 30 m telescope of the Institut de radioastronomie millim\'etrique (IRAM) in April and November-December 2013. We report the detection of ethylene glycol (CH$_2$OH)$_2$ (aGg' conformer) and formamide (NH$_2$CHO) in the two comets. The abundances relative to water of ethylene glycol and formamide are 0.2-0.3% and 0.02% in the two comets, similar to the values measured in comet C/1995 O1 (Hale-Bopp). We also report the detection of HCOOH and CH$_3$CHO in comet C/2013 R1 (Lovejoy), and a search for other complex species (methyl formate, glycolaldehyde).