Laboratory Electronic Spectra of Carbon Chains and Rings

Abstract

AbstractCarriers of the diffuse interstellar bands (DIBs) cannot be definitively identified without laboratory spectra. Several techniques, including matrix isolation, cavity ringdown spectroscopy, resonance enhanced multiphoton ionization, and ion trapping, have been used to measure the electronic spectra of carbon chains and their derivatives. The gas-phase laboratory spectra could then be compared to the astronomical data of known DIBs. The choice of molecules studied in the gas phase depends on the presence of strong electronic transitions at optical wavelengths, the lifetimes of excited electronic states, and chemical feasibility in diffuse astrophysical environments. Collisional-radiative rate models have also be used in conjunction with laboratory spectra to predict absorption profiles under interstellar conditions.