  The noble-gas atom xenon can bind fluorine atoms and form several stable
compounds. We study the electronic structure of the xenon fluorides (XeFn, n =
2,4,6) by calculating their ionization spectra using a Green's function method,
which allows to treat many-body effects at a high level. Our focus is on the
valence region and on the Xe 4d core hole. We observe a sensitive dependence of
the spectra on the number of fluorine ligands. Systematic line shifts are
uncovered and explained. In the Xe 5s and F 2s inner-valence regimes, from XeF2
to XeF6, the usefulness of the one-particle picture of ionization is found to
become progressively worse. Moreover, adding the electronegative fluorine
ligands seems to enhance--not suppress--the Auger decay of a Xe 4d core hole.
