nIFTy galaxy cluster simulations - V. Investigation of the cluster infall region

Research output: Research - peer-reviewArticle

  • External authors:
  • Jake Arthur
  • Frazer R. Pearce
  • Meghan E. Gray
  • Pascal J. Elahi
  • Alexander Knebe
  • Alexander M. Beck
  • Weiguang Cui
  • Daniel Cunnama
  • Romeel Davé
  • Sean February
  • Shuiyao Huang
  • Neal Katz
  • Ian G. McCarthy
  • Giuseppe Murante
  • Valentin Perret
  • Chris Power
  • Ewald Puchwein
  • Alexandro Saro
  • Federico Sembolini
  • Romain Teyssier
  • Gustavo Yepes


We examine the properties of the galaxies and dark matter haloes residing in the cluster infall region surrounding the simulated Λ cold dark matter galaxy cluster studied by Elahi et al. at z = 0. The 1.1 × 1015 h-1M galaxy cluster has been simulated with eight different hydrodynamical codes containing a variety of hydrodynamic solvers and sub-grid schemes. All models completed a dark-matter-only, non-radiative and full-physics run from the same initial conditions. The simulations contain dark matter and gas with mass resolution mDM = 9.01 × 108 h-1M and mgas = 1.9 × 108 h-1M, respectively. We find that the synthetic cluster is surrounded by clear filamentary structures that contain ~60 per cent of haloes in the infall region with mass ~1012.5-1014 h-1M, including 2-3 group-sized haloes (>1013 h-1M). However, we find that only ~10 per cent of objects in the infall region are sub-haloes residing in haloes, which may suggest that there is not much ongoing pre-processing occurring in the infall region at z = 0. By examining the baryonic content contained within the haloes, we also show that the code-to-code scatter in stellar fraction across all halo masses is typically ~2 orders of magnitude between the two most extreme cases, and this is predominantly due to the differences in sub-grid schemes and calibration procedures that each model uses. Models that do not include active galactic nucleus feedback typically produce too high stellar fractions compared to observations by at least ~1 order of magnitude.

Bibliographical metadata

Original languageEnglish
Pages (from-to)2027-2038
Number of pages12
JournalMonthly Notices of the Royal Astronomical Society
Issue number2
Early online date23 Sep 2016
StatePublished - Jan 2017