The Three Hundred Project: The evolution of galaxy cluster density profiles

Robert Mostoghiu, Alexander Knebe, Weiguang Cui, Frazer R. Pearce, Gustavo Yepes, Chris Power, Romeel S Dave, Alexander Arth

Research output: Contribution to journalArticle

Abstract

Recent numerical studies of the dark matter density profiles of massive galaxy clusters (M halo > 10 15 M) show that their median radial mass density profile remains unchanged up to z > 1, displaying a highly self-similar evolution. We verify this by using the data set of the THE THREE HUNDRED project, i.e. 324 cluster-sized haloes as found in full physics hydrodynamical simulations. We track the progenitors of the mass-complete sample of clusters at z = 0, and find that their median shape is already in place by z = 2.5. However, selecting a dynamically relaxed subsample (∼16 per cent of the clusters), we observe a shift of the scale radius r s towards larger values at earlier times. Classifying the whole sample by formation time, this evolution is understood as a result of a two-phase halo mass accretion process. Early-forming clusters – identified as relaxed today – have already entered their slow accretion phase, hence their mass growth occurs mostly at the outskirts. Late-forming clusters – which are still unrelaxed today – are in their fast accretion phase, thus the central region of the clusters is still growing. We conclude that the density profile of galaxy clusters shows a profound self-similarity out to redshifts z ∼ 2.5. This result holds for both gas and total density profiles when including baryonic physics, as reported here for two rather distinct sub-grid models.

Original languageEnglish (US)
Pages (from-to)3390-3403
Number of pages14
JournalMonthly Notices of the Royal Astronomical Society
Volume483
Issue number3
DOIs
Publication statusPublished - Jan 1 2019
Externally publishedYes

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Keywords

  • cosmology theory
  • Dark matter

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

Cite this

Mostoghiu, R., Knebe, A., Cui, W., Pearce, F. R., Yepes, G., Power, C., ... Arth, A. (2019). The Three Hundred Project: The evolution of galaxy cluster density profiles. Monthly Notices of the Royal Astronomical Society, 483(3), 3390-3403. https://doi.org/10.1093/mnras/sty3306