Enhanced formation of interstellar complex organic molecules on carbon monoxide ice

Abstract

We investigate the role of carbon monoxide ice in the chemical evolution of prestellar cores using astrochemical rate equation models. We constrain the ratios of the binding energies on CO ice and H${}_2$O ice for a series of adsorbates deemed important in diffusive chemistry on H${}_2$O ices. We later include these ratios in our chemical reaction network model, where the binding and diffusion energies of icy species vary as a function of the surface composition. When the surface coverage of CO increases, the model shows an enhancement of O-bearing complex organic molecules, especially those formed from the intermediate products of CO hydrogenation (e.g. HCO) and CH${}_3$/CH${}_2$. Because the binding energy of CH${}_3$/CH${}_2$ is in the right range, its diffusion rate increases significantly with CO coverage. At $T>$14 K and with less influence, enhanced diffusion of HCO also contributes to the increase of the abundances of COM. We find, however, that chemistry is not always enhanced on CO ice and that the temperature and cosmic ray ionization rate of each astronomical object is crucial for this particular chemistry, revealing a highly non-trivial behavior that needs to be addressed on a per-case basis. Our results are highly relevant in the context of interstellar ice observations with JWST.

Accepted for publication in Astronomy and Astrophysics

References in corpus (35)

• Non-thermal desorption from interstellar dust grains via exothermic surface reactions
• An Ice Age JWST inventory of dense molecular cloud ices
• Detection of a branched alkyl molecule in the interstellar medium: iso-propyl cyanide
• Laboratory evidence for efficient water formation in interstellar ices
• Binding energies: new values and impact on the efficiency of chemical desorption
• The Spatial Distribution of Complex Organic Molecules in the L1544 Pre-stellar Core
• Experimental evidence for Glycolaldehyde and Ethylene Glycol formation by surface hydrogenation of CO molecules under dense molecular cloud conditions
• Modeling Complex Organic Molecules in dense regions: Eley-Rideal and complex induced reaction
• Formation of Complex Organic Molecules in Cold Interstellar Environments through non-diffusive grain-surface and ice-mantle chemistry
• Multilayer formation and evaporation of deuterated ices in prestellar and protostellar cores
• A non-energetic mechanism for glycine formation in the interstellar medium
• Gas-grain chemistry in cold interstellar cloud cores with a microscopic Monte Carlo approach to surface chemistry
• Formation of Glycerol through Hydrogenation of CO ice under Prestellar Core Conditions
• Simultaneous Hydrogenation and UV-photolysis Experiments of NO in CO-rich Interstellar Ice Analogues; linking HNCO, OCN-, NH2CHO and NH2OH
• Interstellar formamide (NH${}_2$CHO), a key prebiotic precursor
• Formation of the prebiotic molecule NH${}_2$CHO on astronomical amorphous solid water surfaces: accurate tunneling rate calculations
• Formation of COMs through CO hydrogenation on interstellar grains
• Quantum mechanical simulations of the radical-radical chemistry on icy surfaces
• Hydrogenation at low temperatures does not always lead to saturation: the case of HNCO
• Atom Tunneling in the Water Formation Reaction H${}_2$ + OH $\to$ H${}_2$O + H on an Ice Surface
• Carbon Atom Reactivity with Amorphous Solid Water: H${}_2$O Catalyzed Formation of H${}_2$CO
• Binding Energy Evaluation Platform: A database of quantum chemical binding energy distributions for the astrochemical community
• Hunt for complex cyanides in protostellar ices with JWST: Tentative detection of CH${}_3$CN and C${}_2$H${}_5$CN
• A twist on the reaction of the CN radical with methylamine in the interstellar medium: new hints from a state-of-the-art quantum-chemical study
• The complex organic molecular content in the L1498 starless core
• Formation of Acetaldehyde on CO-rich Ices
• Formation of complex organic molecules on interstellar CO ices? Insights from computational chemistry simulations
• A new model of the chemistry of ionizing radiation in solids: CIRIS
• On the relevance of the H2 + O reaction pathway for the surface formation of interstellar water - A combined experimental and modeling study
• Chemical complexity of phosphorous bearing species in various regions of the Interstellar medium
• Acetaldehyde binding energies: a coupled experimental and theoretical study
• A New "Non-energetic" Route to Complex Organic Molecules in Astrophysical Environments: The C + H${}_2$O $\to$ H${}_2$CO Solid-state Reaction
• Cracking the Puzzle of CO2 Formation on Interstellar Ices. Quantum Chemical and Kinetic Study of the CO + OH -> CO2 + H Reaction
• The formation of CO${}_2$ through consumption of gas-phase CO on vacuum-UV irradiated water ice
• Resonant infrared irradiation of CO and CH3OH interstellar ices

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