2003/05/31 by A. Voevodkin, Alexey Voevodkin, A. Vikhlinin · 3 citations
Mathematics · Physics and Astronomy · #Amplitude #Astrophysics #Baryon #Cluster (spacecraft) #Cosmology and Gravitation Theories #Function (biology) #Galaxies: Formation, Evolution, Phenomena #Galaxy #Mass fraction #Mathematical analysis #Mathematics #Physics #Power function #Proxy (statistics) #Quantum mechanics #Redshift #Scientific Research and Discoveries #Spectral density #Statistical physics #Statistics #Thermodynamics #astro-ph
paper · pdf · doi:10.1086/380818
published as Astrophys.J. 601 (2004) 610-620 · 11 pages, ApJ in press. Minor changes to synchronize with the accepted version
arxiv created 2003/10/22 · openalex publication_date 2004/02/01 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We derive the baryon mass function for a complete sample of low-redshift clusters and argue that it is an excellent proxy for the total mass function if the ratio f b = M b / M tot in all clusters is close to its universal value, Ω b /Ω M . Under this assumption, the baryon mass function can be used to constrain the amplitude and slope of the density fluctuation power spectrum on cluster scales. This method does not use observational determinations of the total mass and thus bypasses major uncertainties in the traditional analyses based on the X-ray temperature function. However, it is sensitive to possible systematic variations of the baryon fraction as a function of cluster mass. Adapting a weak dependence f b , suggested by observations and numerical simulations by Bialek et al., we derive σ 8 = 0.72 ± 0.04 and the shape parameter Ω M h = 0.13 ± 0.07, in good agreement with a number of independent methods. We discuss the sensitivity of these values to other cosmological parameters and to different assumptions about variations in f b .