A Good Mass Proxy for Galaxy Clusters with XMM-Newton

We use a sample of 39 galaxy clusters at redshift z < 0.1 observed by XMM-Newton to investigate the relations between X-ray observables and total mass. Based on central cooling time and central temperature drop, the clusters in this sample are divided into two groups: 25 cool core clusters and 14 non-cool core clusters, respectively. We study the scaling relations of L _bol-M ₅₀₀, M ₅₀₀-T, M ₅₀₀-M _g, and M ₅₀₀-Y _X, and also the influences of cool core on these relations. The results show that the M ₅₀₀-Y _X relation has a slope close to the standard self-similar value, has the smallest scatter and does not vary with the cluster sample. Moreover, the M ₅₀₀-Y _X relation is not affected by the cool core. Thus, the parameter of Y_X may be the best mass indicator.