In astrophysical simulations, a crucial issue is that of the construction of initial conditions. I review here one of the commonly used techniques to create initial conditions for N-body simulations. I describe the problem of creating an N-body realization of a spherical system with a given density prole, using the distribution function obtained from Eddington's formula. Such models, consisting of dark matter and gas, may then be used to simulate mergers of galaxy clusters.

numerical simulations, hydrodynamical simulations, extragalactic astrophysics, galaxy clusters.

[1] BINNEY J & TREMAINE S. 1987. Galactic Dynamics, Princeton University Press.

[2] DEHNEN W & READ JI. 2011. European Physical Journal Plus, 126, 55.

[3] EDDINGTON AS. 1916. MNRAS, 76, 572.

[4] HERNQUIST L. 1990. ApJ, 356, 359.

[5] KAZANTZIDIS S, MAGORRIAN J & MOORE B. 2004. ApJ, 601, 37.

[6] KAZANTZIDIS S, ZENTNER AR & KRAVTSOV AV. 2006. ApJ, 641, 647.

[7] MACHADO REG & ATHANASSOULA E. 2010. MNRAS, 406, 2386.

[8] NAVARRO JF, FRENK CS & WHITE SDM. 1997. ApJ, 490, 493.

[9] RODIONOV SA, ATHANASSOULA E & SOTNIKOVA NY. 2009. MNRAS, 392,904.

[10] SPRINGEL V. 2005. MNRAS, 364, 1105.

[11] SPRINGEL V. 2010. ARAA, 48, 391.

[12] ZUHONE JA, MARKEVITCH M & JOHNSON RE. 2010. ApJ, 717, 908.