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The biasing of baryons on the cluster mass function and cosmological parameter estimation

2013/07/31 by Davidé Martizzi, Davide Martizzi, Irshad Mohammed +2 · 63 citations
Physics and Astronomy · #Astronomy and Astrophysical Research #Astrophysics #Baryon #Cluster (spacecraft) #Cosmology and Gravitation Theories #Dark matter #Galaxies: Formation, Evolution, Phenomena #Galaxy #Galaxy cluster #Halo #Halo mass function #Physics #astro-ph.CO

paper · pdf · doi:10.1093/mnras/stu440

published in Monthly Notices of the Royal Astronomical Society 440(3), 2290-2299 (Oxford University Press) · 12 pages, 3 tables, 6 figures, accepted for publication in MNRAS

arxiv created 2014/03/05 · openalex publication_date 2014/04/04 · arxiv updated 2015/06/16 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05

Abstract

We study the effect of baryonic processes on the halo mass function in the galaxy cluster mass range using a catalogue of 153 high-resolution cosmological hydrodynamical simulations performed with the AMR code ramses. We use the results of our simulations within a simple analytical model to gauge the effects of baryon physics on the halo mass function. Neglect of AGN feedback leads to a significant boost in the cluster mass function similar to that reported by other authors. However, including AGN feedback not only gives rise to systems that are similar to observed galaxy clusters, but they also reverse the global baryonic effects on the clusters. The resulting mass function is closer to the unmodified dark matter halo mass function but still contains a mass dependent bias at the 5–10 per舁cent level. These effects bias measurements of the cosmological parameters, such as σ8 and Ωm. For current cluster surveys baryonic effects are within the noise for current survey volumes, but forthcoming and planned large SZ, X-ray and multiwavelength surveys will be biased at the per舁cent level by these processes. The predictions for the halo mass function including baryonic effects need to be carefully studied with larger and improved simulations. However, simulations of full cosmological boxes with the resolution we achieve and including AGN feedback are still computationally challenging.

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