Valence band photoionization of CO2 has been studied by photoelectron
spectroscopy using a velocity map imaging spectrometer and synchrotron
radiation. The measured data allow retrieving electronic and vibrational
branching ratios, vibrationally resolved asymmetry parameters, and the total
electron yield which includes multiple strong resonances. Additionally, the
spectrum of low kinetic energy electrons has been studied in the resonant
region, and the evolution with photon energy of one of the forbidden
transitions present in the slow photoelectrons spectrum has been carefully
analyzed, indicating that in the presence of auto-ionizing resonances the
vibrational populations of the ion are significantly redistributed