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arXiv · 1901.09378

Evolution of superclusters in the cosmic web

J. Einasto·I. Suhhonenko·L. J. Liivamägi·M. Einasto
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Abstract

Aims. We investigate how properties of the ensemble of superclusters in the cosmic web evolve with time. Methods. We perform numerical simulations of the evolution of the cosmic web using the LambdaCDM model in box sizes L0 = 1024, 512, 256 Mpc/h. We find supercluster ensembles of models for four evolutionary stages, corresponding to the present epoch z = 0, and to redshifts z = 1, z = 3, and z = 10. We calculate fitness diameters of superclusters defined from volumes of superclusters divided to filling factors of over-density regions. Geometrical and fitness diameters of largest superclusters, and the number of superclusters as functions of the threshold density are used as percolation functions to describe geometrical properties of the ensemble of superclusters in the cosmic web. We calculate distributions of geometrical and fitness diameters and luminosities of superclusters, and follow time evolution of percolation functions and supercluster distributions. We compare percolation functions and supercluster distributions of models and samples of galaxies of the Sloan Digital Sky Survey (SDSS). Results. Our analysis shows that fitness diameters of superclusters have a minimum at certain threshold density. Fitness diameters around minima almost do not change with time in co-moving coordinates. Numbers of superclusters have maxima which are approximately constant for all evolutionary epochs. Geometrical diameters of superclusters decrease during the evolution of the cosmic web; luminosities of superclusters increase during the evolution. Conclusions. Our study suggests that evolutionary changes occur inside dynamical volumes of superclusters. The stability of fitness diameters and numbers of superclusters during the evolution is an important property of the cosmic web.

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J. Einasto, I. Suhhonenko, L. J. Liivamägi, M. Einasto. 2019-01-27. Evolution of superclusters in the cosmic web. https://doi.org/10.1051/0004-6361%2F201834450

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