Methanol formation chemistry with revised reactions scheme

TL;DR

This study investigates how revised hydrogen abstraction reactions on interstellar grain surfaces affect methanol formation and destruction, revealing significant impacts on molecular abundances in cold dark cloud environments.

Contribution

The paper introduces a revised reaction scheme including experimentally evaluated surface reactions, showing their critical role in methanol chemistry in interstellar conditions.

Findings

Hydrogen abstraction reactions significantly reduce methanol abundance.

Maximum methanol levels decrease by 2-3 orders of magnitude with these reactions.

Binding energies of radicals influence methanol formation pathways.

Abstract

The aim of the presented work is to analyze the impact of experimentally evaluated reactions of hydrogen abstraction on surfaces of interstellar grains on the chemical evolution of methanol and its precursors on grains and in the gas phase under conditions of cold dark cloud and during the collapse of the translucent cloud into the dark cloud. Analysis of simulation results shows that those reactions are highly efficient destruction channels for HCO and H2CO on grain surfaces, and significantly impact the abundances of almost all molecules participating in the formation of CH3OH. Next, in models with those reactions maximum abundances of methanol in gas and on grain surface decrease by more than 2-3 orders of magnitude in comparison to models without surface abstraction reactions of hydrogen. Finally, we study the impact of binding energies of CH2OH and CH3O radicals on methanol chemistry.