The distribution of iron in the Perseus cluster
The distribution of iron in the Perseus cluster
复制标题
英仙座星团中铁的分布
作者：
T. Ponman;D. Bertram;M. Church;C. Eyles;M. P. Watt;G. Skinner;A. Willmore
弥漫在星系团中的热气体（~108K）可能是初始密度扰动后遗留下来的原始物质，也可能是从星系团中喷射出来的气体。在星系团X射线光谱中检测到的铁发射特征证明，至少有一些星系团内介质（ICM）不是原始的，许多星系团的理论模型都是基于整个ICM来自星系的假设。我们在这里报告硬X射线光谱成像观测英仙座集群获得的编码掩模X射线望远镜的Spacelab 2揭示了铁丰度梯度的ICM。ICM的大部分似乎是原始的，富含铁的气体大部分被限制在星系团核心，可能是通过剥离星系团而沉积的。解释X射线光谱所需的铁的总质量远小于化学均匀ICM的基础上所假设的。
THE hot (~108K) gas that permeates clusters of galaxies may be primordial matter left over from the initial density perturbation that grew into the cluster, or may be gas ejected from cluster galaxies. The detection of iron emission features in cluster X-ray spectra proves that at least some of the intracluster medium (ICM) is not primordial, and much theoretical modelling of clusters has been based on the assumption that the entire ICM derives from the galaxies. We report here hard-X-ray spectral imaging observations of the Perseus cluster obtained with the coded-mask X-ray telescope on Spacelab 2 which reveal an iron abundance gradient in the ICM. Most of the ICM seems to be primordial, with the iron-rich gas confined largely to the cluster core where it was probably deposited by stripping of cluster galaxies. The total mass of iron required to explain the X-ray spectra is substantially smaller than has been assumed on the basis of a chemically homogeneous ICM.