SIMBAD references

2004ApJ...601..610V - Astrophys. J., 601, 610-620 (2004/February-1)

Constraining amplitude and slope of the mass fluctuation spectrum using a cluster baryon mass function.


Abstract (from CDS):

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 fb=Mb/Mtotin all clusters is close to its universal value, ΩbM. 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 fbM, suggested by observations and numerical simulations by Bialek et al., we derive σ8=0.72±0.04 and the shape parameter ΩMh=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 fb.

Abstract Copyright:

Journal keyword(s): Cosmology: Cosmological Parameters - Galaxies: Clusters: General - Surveys - X-Rays: Galaxies: Clusters

CDS comments: Table 1 : Objects with truncated designation are : 2A 0335+096 and EXO 0422-086

Simbad objects: 52

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