Dynamical state of galaxy clusters evaluated from X-ray images

TL;DR

This study evaluates the dynamical states of over 1300 galaxy clusters using X-ray imaging from XMM-Newton and Chandra, introducing new morphological parameters and confirming consistency across datasets.

Contribution

It introduces a comprehensive method to assess galaxy cluster dynamics using multiple X-ray morphological parameters and applies it to a large, diverse sample.

Findings

Good consistency between XMM-Newton and Chandra dynamical parameters.

Dynamical state influences mass scaling relations.

Enhanced dynamical parameters for 42 clusters with updated redshifts.

Abstract

X-ray images of galaxy clusters often show disturbed structures that are indication of cluster mergers. As a complementary to our previous work on dynamical state of 964 clusters observed by the Chandra, we process the X-ray images for 1308 clusters from XMM-Newton archival data, together with the images of 22 clusters newly released by the Chandra, and evaluate their dynamical state from these X-ray images. The concentration index $c$, the centroid shift $\omega$, the power ratio $P_3/P_0$ are calculated in circular regions with a certain radius of 500 kpc, and the morphology index $\delta$ is estimated within elliptical regions adaptive to the cluster size and shape. In addition, the dynamical parameters for 42 clusters previously estimated from Chandra images are upgraded based on the newly available redshifts. Good consistence is found between dynamical parameters derived from XMM-Newton and Chandra images for the overlapped sample of clusters in the two datasets. The dependence of mass scaling relations on dynamical state is shown by using data of 388 clusters.