Testing for X-ray-SZ Differences and Redshift Evolution in the X-ray Morphology of Galaxy Clusters

Understand

We present a quantitative study of the X-ray morphology of galaxy clusters, as a function of their detection method and redshift.

• We analyze two separate samples of galaxy clusters: a sample of 36 clusters at 0.35 < z < 0.9 selected in the X-ray with the ROSAT PSPC 400 deg2 survey, and a sample of 90 clusters at 0.25 < z < 1.2 selected via the Sunyaev-Zel'dovich (SZ) effect with the South Pole Telescope.
• Clusters from both samples have similar-quality Chandra observations, which allow us to quantify their X-ray morphologies via two distinct methods: centroid shifts and photon asymmetry.
• The latter technique provides nearly unbiased morphology estimates for clusters spanning a broad range of redshift and data quality.