Astronomical School’s Report, 2017, Volume 13, Issue 2, Pages 81–84

https://doi.org/10.18372/2411-6602.13.12
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UDC 524.8:519.2

Simulation of large-scale structure of Universe with Gaussian random fields

Tugay A.V., Voytsehovsky V.V.

Taras Shevchenko National University of Kyiv, Hlushkova Avenue 4a, 03127 Kyiv, Ukraine

Abstract

Large-scale structure includes galaxy clusters connected by filaments. Voids occupy the rest of cosmic volume. In this work we simulated two-dimensional galaxy distribution using random distributions of clusters and single galaxies. The main assumption was that matter clustered to initial density fluctuation with uniform distribution. In cosmological theory of gravitational instability primordial perturbations are considered as Gaussian. According to Zeldovich theory, low-dimensional anisotropies should increase, that corresponds to appearance of filaments in 2D case. The motivation for 2D consideration of large-scale structure is “finger of God” effect concerned with peculiar velocities of galaxies in clusters. We considered layers of 100 Mpc by radial distance that correspond to one void or supercluster. To simulate cosmic web we generated a net of filaments between clusters with certain length limits. Real galaxy distribution was simulated by changing of random positions of galaxies in filaments and clusters. We generated galaxies in clusters by nonlinear dependencies from surrounding clusters and add uniform distribution of isolated galaxies in voids. The distribution of our model correlate well with the available observations of the Universe at large scales such as Sloan Digital Sky Survey. We selected SDSS galaxies at distances from 100 to 200 Mpc that corresponds to position of Coma supercluster. More distant regions has large deficit of galaxies due to selection effect. Numerical measure for comparison of galaxy distribution is two-point correlation function or power spectrum. Further calculation of correlation function will allow to select optimal parameters of simulation for the best correspondence with real matter distribution.

Keywords: large-scale structure of Universe; galaxies: clusters; galaxies: formation

References

  1. Wang Y., Bunner R.J., Dolence J.C. The SDSS Galaxy Angular Two-Point Correlation Function. arXiv:1303.2432v2. https://doi.org/10.1093/mnras/stt450
  2. Vavilova I. Velykomasshtabna struktura Vsesvitu. Sposterezhennia i metody doslidzhennia. Kyyiv, 1998.
  3. Longeyr M., Eynasto Ya. Krupnomasshtabnaya struktura Vselennoy. M., 1981.
  4. Pibls F.Dzh.E. Struktura Vselennoy v bol’shikh masshtabakh. M.: Mir, 1983.
  5. Tugay A.V. (2014). Extragalactic filament detection with a layer smoothing method. Advances in Astronomy and Space Physics, 4, 42–45. https://doi.org/10.17721/2227-1481.4.42-45
  6. Ivashchenko G., Zhdanov V.I., Tugay A.V. (2010). Correlation function of quasars in real and redshift space from the Sloan Digital Sky Survey Data Release 7. Mon. Not. R. Astron. Soc., 409, 1691–1704. https://doi.org/10.1111/j.1365-2966.2010.17411.x
  7. Tugay A.V. (2012). Signatures of large-scale structure of Universe in X-rays. Odessa Astronomy Publications. –2012. – Vol. 25., 142–144.

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