New light on the baryon fraction in galaxy clusters
نویسندگان
چکیده
منابع مشابه
New light on the baryon fraction in galaxy clusters
Baryon fraction in clusters, combined with constraints from primordial nucleosynthesis is currently used to provide a robust upper limit on the cosmological density parameter Ω 0. Current analyses lead to gas fractions at virial radius which are typically of the order of 0.20h −3/2 50 , favoring a low density universe. In this work, we examine critically this issue through the analysis of the b...
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The baryon fraction in galaxy clusters is one of the most direct way to constrain Ω0. The baryonic fraction is estimated to be in the range fb = (0.15 − 0.20) h −3/2 50 which is several times higher than expected from the observed light element abundances in Ω0 = 1 universe, leading to the conclusion that we live in low density universe. In this work I will first present the various steps which...
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We study the baryon mass fraction in a set of hydrodynamical simulations of galaxy clusters performed using the Tree+SPH code GADGET-2. We investigate the dependence of the baryon fraction upon the radiative cooling, star formation, feedback through galactic winds, conduction and redshift. Both the cold stellar component and the hot X-ray emitting gas have narrow distributions that, at large cl...
متن کاملThe stellar mass fraction and baryon content of galaxy clusters and groups
The analysis of a sample of 52 clusters with precise and hypothesis-parsimonious measurements of mass, derived from caustics based on about 208 member velocities per cluster on average, shows that low-mass clusters and groups are not simple scaled-down versions of their massive cousins in terms of stellar content: lighter clusters have more stars per unit cluster mass. The same analysis also sh...
متن کاملHierarchical clustering and the baryon distribution in galaxy clusters
The baryon fraction of galaxy clusters in numerical simulations is found to be dependant on the cluster formation method. In all cases, the gas is anti-biased compared with the dark matter. However, clusters formed hierarchically are found to be more depleted in baryons than clusters formed non-hierarchically. There is a depletion of 10 to 15% for hierarchically formed clusters while the deplet...
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ژورنال
عنوان ژورنال: Astronomy & Astrophysics
سال: 2001
ISSN: 0004-6361,1432-0746
DOI: 10.1051/0004-6361:20010347