1307.0568 (Z. L. Wen et al.)

Substructure and dynamical state of 2092 rich clusters of galaxies derived from photometric data    [PDF]

Z. L. Wen, J. L. Han

Dynamical state of galaxy clusters is closely related to observational properties in X-ray, optical and radio wavelengths. A few hundred clusters have their dynamical states previously quantified based on substructures in X-ray and optical data. We develop a method to diagnose the substructure of projected distribution and dynamical state of galaxy clusters by using photometric data of Sloan Digital Sky Survey (SDSS). To trace the light and mass distribution, the brightness distribution of member galaxies is smoothed by using a Gaussian kernel with a weight of their optical luminosities. After deriving the asymmetry, the ridge flatness and the normalized deviation of the smoothed optical map, we define a relaxation parameter, $\Gamma$, to quantify dynamical state of clusters. This method is applied to a test sample of 98 clusters of $0.05View original: http://arxiv.org/abs/1307.0568