  Recent Suzaku X-ray observations revealed that the observed entropy profile
of the intracluster medium (ICM) deviates significantly from the prediction of
hydrodynamical simulations of galaxy clusters. In this work, we show that gas
clumping introduces significant biases in X-ray measurements of the ICM
profiles in the outskirts of galaxy clusters. Using hydrodynamical simulations
of galaxy cluster formation in a concordance Lambda-CDM model, we demonstrate
that gas clumping leads to an overestimate of the observed gas density and
causes flattening of the entropy profile. Our results suggest that gas clumping
must be taken into account when interpreting X-ray measurements of cluster
outskirts.
