Multi-wavelength Investigations of Galaxy-Hot Plasma Interactions in Clusters of Galaxies

我们继续并扩展了研究主题，即星系进入星系团中心的宇宙学陷落（最初由Makishima等人在2001年提出），通过对三个主要质量分量进行更全面的研究，即，我们与中国天文台的光学天文学家（韩教授和温博士）合作，收集了340个红移范围在0.1-0.5的星系团样本。样本量是Gu等人（2013）中使用的样本量的10倍。在这项工作中，我在分析X射线和光学数据方面发挥了核心作用。继Gu et al.（2013）之后，我们发现了宇宙学时间尺度上的一个重大演变：星系相对于ICM和暗物质随着时间的推移而集中，而ICM与暗物质相比一直在膨胀，即使它们继续辐射。这种演化不仅仅是由引力效应驱动的，比如星系和星系团物质之间的动力学摩擦。结果将很快提交给《天体物理学杂志》。等人2001，PASJ，53，401; Gu，L.等人2013，ApJ，767，157; Gu，L.等人，2014，in prep.

We have continued and extended the research topic, the cosmological infall of galaxies into the centre of galaxy clusters (originally proposed by Makishima et al. 2001), by carrying out a much more comprehensive study on the three main mass components i.e., galaxies, hot ICM, and dark matter, in the galaxy clusters.In collaborating with optical astronomers (Prof. Han and Dr. Wen) in National Observatory of China, we compiled a sample of 340 galaxy clusters in redshift range of 0.1-0.5. The size of the sample is 10 times as the one used in Gu et al. (2013). In this work I played a central role in analyzing both X-ray and optical data. We have detected, following Gu et al. (2013), a significant evolution on a cosmological timescale: galaxies have been centrally concentrated with time relative to the ICM and dark matter, while the ICM has been expanding compared to dark matter even they keep radiating. This evolution is not solely driven by gravitational effects such as dynamical friction between galaxies and cluster matters. The result will be submitted soon to the Astrophysical Journal.References: Makishima, K. et al. 2001, PASJ, 53, 401; Gu, L. et al. 2013, ApJ, 767, 157; Gu, L. et al. 2014, in prep.