论文标题
Chandra X射线图像的964个星系簇的动力状态
Dynamical state for 964 galaxy clusters from Chandra X-ray images
论文作者
论文摘要
星系簇的动态状态描述了簇是在动态放松还是在子观测值的合并过程中。通过使用Chandra X射线观测站的档案图像，我们得出了一组参数来描述964个Galaxy簇的动态状态。动态状态的三个广泛使用的指标，浓度指数C，质心移动欧米茄和功率比P3/P0在半径为500 kpc的圆形中央区域中计算。我们还在最佳拟合椭圆形区域中得出了两个自适应参数，分别是剖面参数kappa和不对称因子alpha。然后，通过组合这两个自适应参数来定义形态指数增量，该参数指示了星系簇的动态状态，并且与浓度指数C，质心移位欧米茄，功率比P3/p0的浓度指数具有良好的相关性，以及光放松因子γ。对于大量簇样本，动态参数是从受干扰到放松状态的峰值连续分布的，而峰值则在两个状态的双峰分布之间连续分布。我们发现，新得出的形态指数DELTA适用于无线电功率，群集质量和动态状态之间的类似基本平面，用于具有弥漫性无线电巨头巨头和迷你山谷的群集。根据Sunyaev-Zeldovich效应和X射线图像估计的质量之间的偏移取决于动态参数。从Chandra档案图像衍生的Galaxy簇的所有动力学参数均在http://zmtt.bao.ac.cn/galaxy_clusters/dyximages/上获得。
The dynamical state of galaxy clusters describes if clusters are relaxed dynamically or in a merging process of subclusters. By using archival images from the Chandra X-ray Observatory, we derive a set of parameters to describe the dynamical state for 964 galaxy clusters. Three widely used indicators for dynamical state, the concentration index c, the centroid shift omega and the power ratio P3/P0 are calculated in the circular central region with a radius of 500 kpc. We also derive two adaptive parameters, the profile parameter kappa and the asymmetry factor alpha, in the best fitted elliptical region. The morphology index delta is then defined by combining these two adaptive parameters, which indicates the dynamical state of galaxy clusters and has good correlations to the concentration index c, the centroid shift omega, the power ratio P3/P0, and the optical relaxation factor Gamma. For a large sample of clusters, the dynamical parameters are continuously distributed from the disturbed to relaxed states with a peak in the between, rather than the bimodal distribution for the two states. We find that the newly derived morphology index delta works for the similar fundamental plane between the radio power, cluster mass and the dynamical state for clusters with diffuse radio giant-halos and mini-halos. The offset between masses estimated from the Sunyaev-Zeldovich effect and X-ray images depends on dynamical parameters. All dynamical parameters for galaxy clusters derived from the Chandra archival images are available on http://zmtt.bao.ac.cn/galaxy_clusters/dyXimages/.
