  Recently we have shown that the centrality dependence of the multiplicity of
different hadron species observed in RHIC and SPS experiments can be well
understood in a simple model, dubbed core-corona model. There it is assumed
that those incoming nucleons which scatter only once produce hadrons as in pp
collisions whereas those which scatter more often form an equilibrated source
which decays according to phase space. In this article we show that also
kinematical variables like $v_2/\epsilon_{part} (N_{part})$ as well as
$v_2^i/\epsilon_{part} (N_{part})$ and $<p_T^i (N_{part})>$ of identified
particles are well described in this model. The correlation of $<p_T^i>$
between peripheral heavy ion collisions and pp collisions for different
hadrons, reproduced in this model, questions whether hydrodynamical
calculations are the proper tool to describe non-central heavy ion collision.
The model explains as well the centrality dependence of $v_2/\epsilon_{part}$
of charged particles, considered up to now as an observable which allows to
determine the viscosity of the quark gluon plasma. The observed dependence of
$v_2^i/\epsilon_{part}(N_{part})$ on the particle species is a simple
consequence of the different ratios of core to corona particles.
