Ethylene oxide and Acetaldehyde in hot cores

Abstract

[Abridged] Ethylene oxide and its isomer acetaldehyde are important complex organic molecules because of their potential role in the formation of amino acids. Despite the fact that acetaldehyde is ubiquitous in the interstellar medium, ethylene oxide has not yet been detected in cold sources. We aim to understand the chemistry of the formation and loss of ethylene oxide in hot and cold interstellar objects (i) by including in a revised gas-grain network some recent experimental results on grain surfaces and (ii) by comparison with the chemical behaviour of its isomer, acetaldehyde. We test the code for the case of a hot core. The model allows us to predict the gaseous and solid ethylene oxide abundances during a cooling-down phase prior to star formation and during the subsequent warm-up phase. We can therefore predict at what temperatures ethylene oxide forms on grain surfaces and at what temperature it starts to desorb into the gas phase. The model reproduces the observed gaseous abundances of ethylene oxide and acetaldehyde towards high-mass star-forming regions. In addition, our results show that ethylene oxide may be present in outer and cooler regions of hot cores where its isomer has already been detected. Despite their different chemical structures, the chemistry of ethylene oxide is coupled to that of acetaldehyde, suggesting that acetaldehyde may be used as a tracer for ethylene oxide towards cold cores.

arXiv comment11 pages, 5 figures. Accepted by A&A

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Cited by in corpus (7)

• Formation of Complex Molecules in Prestellar Cores: a Multilayer Approach
• UCLCHEM: A Gas-Grain Chemical Code
• The ALMA-PILS survey: First detections of ethylene oxide, acetone and propanal toward the low-mass protostar IRAS 16293-2422
• Chemical complexity induced by efficient ice evaporation in the Barnard 5 molecular cloud
• A Search for Heterocycles in GOTHAM Observations of TMC-1
• Hydrogenation of acetaldehyde on interstellar ice analogs reveals limited destruction
• First detection of ethylene oxide and acetaldehyde in hot core G358.93$-$0.03 MM1: Tracing prebiotic oxygen chemistry