Carbon‐Chain Oxides in Proton‐Irradiated CO Ice Films

Abstract

After H 2 and water, CO and CO 2 are the most common molecules in stellar and interstellar environments. They are often dominant components in icy mantles of comets and interstellar dust grains. These ice mantles are subject to a varying degree of cosmic radiation, leading to chemical alterations. This paper presents a study of the near-IR absorption spectrum (1900-4000 cm -1 ) of proton-irradiated CO thin films. The spectra of such films display several features arising in the vicinity of the CO fundamental that are attributed to carbon oxides such as C n O and C n O 2 for n ≤ 7. The formation mechanisms of carbon chains in interstellar environments are of interest since carbon chains (or molecules derived from them) have been considered to be carriers of some of the diffuse interstellar bands.