<span Class="roman">si</span>_{<span Class="roman">n</span>}<span Class="roman">o</span>_{<span Class="roman">m</span>}^{<span Class="roman">+</span>} – Optical Absorption And Photodissociation Properties

Interstellar dust contains to a large extent $\mu$m-sized silicate particles. The origin and evolutionary processes of these are still poorly understood. Only one possible precursor, molecular SiO in a circumstellar disk, has been observed so far.$^{[1]}$ We present experimental data and quantum chemical calculations on the absorption and dissociation properties of small \chem{Si_nO_m^+} clusters ($n=10-12$, $m=1-2$) that are potential intermediates between the circumstellar SiO diatomic molecule and silicate grains observed in the interstellar medium. The spectra are the first optical absorption spectra of \chem{Si_nO_m^+} cations and obtained by photodissociation of mass-selected ions generated in a laser desorption source.$^{[2]}$ We compare our experimental results to TD-DFT calculations and discuss them in an astrophysical context.\\ \newline Literature: [1] R. Wilson et al., Astrophys. J., 1971, 167, L97. [2] M. Förstel et al., Rev. Sci. Instrum., 2017, 88, 123110