Electron-attachment rates for carbon-rich molecules in protoplanetary atmospheres: the role of chemical differences

TL;DR

This study models electron attachment rates for carbon-rich molecules in protoplanetary atmospheres, revealing that each molecule requires specific parametrization, challenging the use of a universal rate for polyynes.

Contribution

It provides quantum-based calculations of electron attachment rates for polyynes, highlighting the chemical differences affecting these rates in astrophysical environments.

Findings

Attachment rates vary significantly between different polyynes.

A universal parametrization for all polyynes is not valid.

Quantum collision dynamics effectively model interstellar molecule interactions.

Abstract

The formation of anionic species in the interstellar medium from interaction of linear molecules containing carbon, nitrogen and hydrogen as atomic components (polyynes) with free electrons in the environment is modelled via a quantum treatment of the collision dynamics. The ensuing integral cross sections are employed to obtain the corresponding attachment rates over a broad range of temperatures for the electrons. The calculations unequivocally show that a parametrization form often employed for such rates yields a broad range of values that turn out to be specific for each molecular species considered, thus excluding using a unique set for the whole class of polyynes.