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arXiv · 1709.07457

Internal dark matter structure of the most massive galaxy clusters

Amandine M. C. Le Brun·Monique Arnaud·Gabriel W. Pratt·Romain Teyssier
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Abstract

We investigate the evolution of the dark matter density profiles of the most massive galaxy clusters in the Universe. Using a `zoom-in' procedure on a large suite of cosmological simulations of total comoving volume of $3\,(h^{-1}\,\rm Gpc)^3$, we study the 25 most massive clusters in four redshift slices from $z\sim 1$ to the present. The minimum mass is $M_{500} > 5.5 \times 10^{14}$ M$_{\odot}$ at $z=1$. Each system has more than two million particles within $r_{500}$. Once scaled to the critical density at each redshift, the dark matter profiles within $r_{500}$ are strikingly similar from $z\sim1$ to the present day, exhibiting a low dispersion of 0.15 dex, and showing little evolution with redshift in the radial logarithmic slope and scatter. They have the running power law shape typical of the NFW-type profiles, and their inner structure, resolved to $3.8\,h^{-1}$ comoving kpc at $z=1$, shows no signs of converging to an asymptotic slope. Our results suggest that this type of profile is already in place at $z>1$ in the highest-mass haloes in the Universe, and that it remains exceptionally robust to merging activity.

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Amandine M. C. Le Brun, Monique Arnaud, Gabriel W. Pratt, Romain Teyssier. 2017-09-21. Internal dark matter structure of the most massive galaxy clusters. https://doi.org/10.1093/mnrasl%2Fslx150

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