The excitation mechanism of the lowest-energy satellite bands in the C 1s core level photoemission of CO2

The lowest-energy satellite bands accompanying the C 1s main line have been investigated, using angle-revolved photoelectron spectroscopy. We find that these satellite bands are resonantly enhanced at the same. photon energy as the shape resonance of the main line. This observation contradicts the predictions based on the shake-up model, and suggests a dominant role of the final state correlations arising from the interaction between a primary photoelectron and a valence electron.