  We have calculated photoionization cross-section of endohedral atoms A@CN. We
took into account the polarizability of the fullerene electron shell CN that
modifies the incoming photon beam and the one-electron wave functions of the
caged atom A. We employ simplified versions of both static and dynamic
polarization. The properly modified one-electron wave functions became a
starting point of the account of the multi-electron correlations in the frame
of the random phase approximation with exchange (RPAE). We treat atomic and
fullerenes polarization that act upon photoelectron similarly, substituting
them by static polarization potential. The photon beam polarizes the fullerene.
This effect is accounted for introducing a polarization factor. As concrete
objects, we have considered Ar and Xe atoms inside fullerene C60. Inclusion of
polarization prominently increases the photoionization cross-section mainly
close to the threshold.
