On the possible contribution of cationic oxygenated carbon chains CnO+, HCnO+, and OCnO+ (n = 4 − 9) to the diffuse interstellar bands

Abstract Only 4 of the diffuse interstellar bands (DIBs) are currently accounted for, ascribed to electronic transitions C$_{60}^+$. Investigations into carriers other DIBs historically focus on charged and neutral hydrocarbons, little information is available regarding oxygenated carbon hydrocarbon species that result from two most abundant heavy elements in medium, C O. In this study, we assess whether CnO+, HCnO+, OCnO+ (n = − 9) cations viable candidates account for using both density-functional theory (DFT) coupled cluster single-double perturbative triple theory, CCSD(T). For these species, linear structures stable isomers with lowest dissociation threshold corresponding CO loss. Optical absorptions chain characterized by calculated vertical excitation wavelengths their oscillator strengths equation-of-motion CCSD (EOM-CCSD) method. Aside HC4O+ HC2n + 1O+, all considered study have lie visible or near-infrared spectral regions. Minimal column densities necessary been estimated. Based present results known chains TMC-1, growth rate O-bearing via ion-neutral reaction mechanisms judged be too low form a sufficient population give rise DIBs.