A novel framework to study the impact of binding energy distributions on the chemistry of dust grains

TL;DR

This paper introduces a new framework to analyze how distributions of binding energies affect molecular desorption from dust grains, impacting astrochemical models of star and planet formation.

Contribution

The paper presents a novel multi-binding energy framework that incorporates binding energy distributions into astrochemical models, improving the understanding of molecule desorption processes.

Findings

Binding energy distributions significantly influence desorption efficiency.

Surface chemistry outcomes are affected by the range of binding energies.

The new framework alters predictions of molecular abundances in astrophysical environments.

Abstract

The evaporation of molecules from dust grains is crucial to understand some key aspects of the star- and the planet-formation processes. During the warm-up phase the presence of young protostellar objects induces molecules to evaporate from the dust surface into the gas phase, enhancing its chemical complexity. Similarly, in circumstellar disks, the position of the so-called snow-lines is determined by evaporation, with important consequences for the formation of planets. The amount of molecules that are desorbed depends on the interaction between the species and the grain surface, which is controlled by the binding energy. Recent theoretical and experimental works point towards a distribution of values for this parameter instead of the single value often employed in astrochemical models.We present here a new "multi-binding energy" framework, to assess the effects that a distribution of binding energies has on the amount of species bound to the grains. We find that the efficiency of the surface chemistry is significantly influenced by this process with crucial consequences on the theoretical estimates of the desorbed species.