Dynamical Properties and Velocity Dispersion-Mass Relation of $z \sim 1$ Galaxy Clusters from the GOGREEN and GCLASS Surveys

Abstract

We investigate a sample of 14 galaxy clusters from the GOGREEN and GCLASS (GG) spectroscopic datasets within the redshift range $(0.87 \leq z \leq 1.37)$ and cluster masses $\mathrm{M}_{200} \gtrsim 2\times 10^{14}$ \hm. Using the highly effective GalWeight technique for cluster membership assignment developed by our own team, we derive the dynamical parameters of these clusters through the virial mass estimator. We examine the velocity dispersion-cluster mass relation $(\sigma \mathrm{MR})$ for the GG cluster sample. We find, $\log{\sigma_{200}} = (2.94\pm0.02) + (0.37\pm0.07)\log{\mathrm{M}_{200}}$ with an intrinsic scatter of $(\sigma_\mathrm{int} = 0.02 \pm 0.02)$. Our results demonstrate that the $(\sigma \mathrm{MR})$ relation is consistent with predictions from cosmological simulations, highlighting the reliability of the GalWeight technique for cluster membership assignment. Furthermore, the $(\sigma \mathrm{MR})$ validates the robustness of the virial mass estimator in accurately recovering cluster masses and associated parameters. Importantly, our findings confirm that velocity dispersion can be used directly to estimate cluster mass without relying on dynamical mass estimators.