Depletion of FeO in the Interstellar Medium via Its Anion Resonances

Depletion of FeO in the interstellar medium through resonance states of FeO- was studied through collision-induced dissociation of FeO-. Collisional excitation of FeO- lead to the yield of Fe- and O-, with a higher yield for Fe-. The ground electronic state of FeO- was identified to be 6Δ state and the results are compared with previous theoretical and experimental results. The kinetic energy distributions of the fragments revealed two FeO- anion resonances accessed upon excitation and their potential energy curves were evaluated. The role of the observed resonances in the depletion of FeO and the viable presence of Fe- and O- in Sagittarius B2 are discussed.