Cluster Physics with Merging Galaxy Clusters

Frontiers in Astronomy and Space Sciences

Molnar, Sandor M.¹ 

[1] Institute of Astronomy and Astrophysics, Academia Sinica, Taipei, Taiwan

关键词: galaxies;    black holes: astronomical surveys;    galactic evolution;    quasars;    active galactic nuclei;    clusters of galaxies;    optical observations of clusters;    X-ray observations of clusters;    radio observations of clusters;    numerical simulation;   

DOI  :  10.3389/fspas.2015.00007

学科分类：空间科学

来源: Frontiers

【 摘 要 】

Collisions between galaxy clusters provide a unique opportunity to study matter in a parameter space which cannot be explored in our laboratories on Earth. In the standard \LCDM model, where the total density is dominated by the cosmological constant ($\Lambda$) and the matter density by cold dark matter (CDM), structure formation is hierarchical, and clusters grow mostly by merging. Mergers of two massive clusters are the most energetic events in the universe after the Big Bang, hence they provide a unique laboratory to study cluster physics. The two main mass components in clusters behave differently during collisions: the dark matter is nearly collisionless, responding only to gravity, while the gas is subject to pressure forces and dissipation, and shocks and turbulence are developed during collisions. In the present contribution we review the different methods used to derive the physical properties of merging clusters. Different physical processes leave their signatures on different wavelengths, thus our review is based on a multifrequency analysis. In principle, the best way to analyze multifrequency observations of merging clusters is to model them using N-body/\HYDRO numerical simulations. We discuss the results of such detailed analyses. New high spatial and spectral resolution ground and space based telescopes will come online in the near future. Motivated by these new opportunities, we briefly discuss methods which will be feasible in the near future in studying merging clusters.

【 授权许可】

CC BY