The evolution of galaxy cluster X-ray scaling relations
The evolution of galaxy cluster X-ray scaling relations
复制标题
星系团X射线标度关系的演化
DOI：
10.1111/j.1365-2966.2010.17267.x
复制
发表时间：
2010
影响因子：
4.8
通讯作者：
Thailand
中科院分区：
文献类型：
--
作者：
C. Short;P. Thomas;O. Young;F. Pearce;A. Jenkins;O. M. U. O. Sussex;UK.;U. Nottingham;U. Durham;Khon Kaen University;Thailand
我们首次利用数值模拟研究了超新星和活动星系核反馈对星系团X射线标度关系演化的联合影响。我们的模拟来自千年天然气项目，是有史以来最大的流体动力学N体模拟。反馈是使用一个混合的计划，在那里的能量输入到星系团内的气体SNe和活动星系核是从一个半解析模型的星系形成。这确保了反馈的来源是一个非常类似于在真实的宇宙中发现的星系群。我们表明，我们的反馈模型是能够再现所观察到的本地X射线标度律，至少对于非冷核心集群，但几乎相同的结果可以得到一个简单的预热模型。然而，我们证明了这两个模型预测相反的进化行为。我们已经研究了我们的反馈模型预测的演化是否与高红移星系团的观测结果相一致。从广义上讲，我们发现，数据似乎有利于z的反馈模型？0.5，以及在更高的红移预热模型。然而，与观测结果进行统计上有意义的比较是不可能的，因为目前可用的高红移星系团的大样本容易产生强烈的选择偏差。随着观测图像在不久的将来变得更加清晰，应该有可能对标度律的演变施加严格的限制，为我们提供了对星系团中物理过程的宝贵探索。
We use numerical simulations to investigate, for the first time, the joint effect of feedback from supernovae (SNe) and active galactic nuclei (AGN) on the evolution of galaxy cluster X-ray scaling relations. Our simulations are drawn from the Millennium Gas Project and are some of the largest hydrodynamical N-body simulations ever carried out. Feedback is implemented using a hybrid scheme, where the energy input into intracluster gas by SNe and AGN is taken from a semi-analytic model of galaxy formation. This ensures that the source of feedback is a population of galaxies that closely resembles that found in the real Universe. We show that our feedback model is capable of reproducing observed local X-ray scaling laws, at least for non-cool-core clusters, but that almost identical results can be obtained with a simplistic preheating model. However, we demonstrate that the two models predict opposing evolutionary behaviour. We have examined whether the evolution predicted by our feedback model is compatible with observations of high-redshift clusters. Broadly speaking, we find that the data seem to favour the feedback model for z? 0.5, and the preheating model at higher redshift. However, a statistically meaningful comparison with observations is impossible, because the large samples of high-redshift clusters currently available are prone to strong selection biases. As the observational picture becomes clearer in the near future, it should be possible to place tight constraints on the evolution of the scaling laws, providing us with an invaluable probe of the physical processes operating in galaxy clusters.