Constraints on sigma_8 from galaxy clustering in N-body simulations and semi-analytic models

Abstract

We generate mock galaxy catalogues for a grid of different cosmologies, using rescaled N-body simulations in tandem with a semi-analytic model run using consistent parameters. Because we predict the galaxy bias, rather than fitting it as a nuisance parameter, we obtain an almost pure constraint on sigma_8 by comparing the projected two-point correlation function we obtain to that from the SDSS. A systematic error arises because different semi-analytic modelling assumptions allow us to fit the r-band luminosity function equally well. Combining our estimate of the error from this source with the statistical error, we find sigma_8=0.97 +/- 0.06. We obtain consistent results if we use galaxy samples with a different magnitude threshold, or if we select galaxies by b_J-band rather than r-band luminosity and compare to data from the 2dFGRS. Our estimate for sigma_8 is higher than that obtained for other analyses of galaxy data alone, and we attempt to find the source of this difference. We note that in any case, galaxy clustering data provide a very stringent constraint on galaxy formation models.

14 pages, 8 figures; accepted by MNRAS

References in corpus (10)

• Wilkinson Microwave Anisotropy Probe (WMAP) Three Year Results: Implications for Cosmology
• Halo assembly bias and its effects on galaxy clustering
• Cosmological Constraints From the 100 Square Degree Weak Lensing Survey
• The Dependence of the Mass Assembly History of Cold Dark Matter Halos on Environment
• Environmental Dependence of Cold Dark Matter Halo Formation
• Breaking the Degeneracies Between Cosmology and Galaxy Bias
• The Dependence of the Occupation of Galaxies on the Halo Formation Time
• On the Luminosity Dependence of the Galaxy Pairwise Velocity Dispersion
• Cosmic Voids and Galaxy Bias in the Halo Occupation Framework
• Why does the clustering of haloes depend on their formation history

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