X-Ray morphological analysis of the Planck ESZ clusters
  X-ray observations show that galaxy clusters have a very large range of
morphologies. The most disturbed systems which are good to study how clusters
form and grow and to test physical models, may potentially complicate
cosmological studies because the cluster mass determination becomes more
challenging. Thus, we need to understand the cluster properties of our samples
to reduce possible biases. This is complicated by the fact that different
experiments may detect different cluster populations. For example, SZ selected
cluster samples have been found to include a greater fraction of disturbed
systems than X-ray selected samples. In this paper we determined eight
morphological parameters for the Planck Early Sunyaev-Zeldovich (ESZ) objects
observed with XMM-Newton. We found that two parameters, concentration and
centroid-shift, are the best to distinguish between relaxed and disturbed
systems. For each parameter we provide the values that allow one to select the
most relaxed or most disturbed objects from a sample. We found that there is no
mass dependence on the cluster dynamical state. By comparing our results with
what was obtained with REXCESS clusters, we also confirm that indeed the ESZ
clusters tend to be more disturbed, as found by previous studies.
