  The intensities of photoelectron satellite lines, corresponding to double
core hole (DCH) states of Ar 1s ionization by hard X-rays are calculated using
the many-body-perturbation theory. Calculations support the interpretation of
the most intense lines as the shake-up excitations 2p 4p. It is demonstrated
that the intensities of the spectrum lines corresponding to 4s (and 3d) excited
states in DCH field can be explained only taking into account the direct
knock-up process 2p 3d along with shake-up process 1s 4s that accompanies 2p
photoionization.
