2007/09/21 by G. Harker, Geraint Harker, Shaun Cole +1 · 1 citation
Physics and Astronomy · #Astronomy and Astrophysical Research #Astrophysics #Cluster analysis #Constraint (computer-aided design) #Correlation function (quantum field theory) #Cosmology and Gravitation Theories #Galaxies: Formation, Evolution, Phenomena #Galaxy #Galaxy formation and evolution #Luminosity #Luminosity function #Physics #Redshift #Redshift survey #Sky #Statistics #astro-ph
paper · pdf · doi:10.1111/j.1365-2966.2007.12508.x
published as Mon.Not.Roy.Astron.Soc.382:1503-1515, 2007 · 14 pages, 8 figures; accepted by MNRAS
arxiv created 2007/09/21 · openalex publication_date 2007/12/07 · arxiv updated 2011/02/11 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
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 σ8 by comparing the projected two-point correlation function we obtain to that from the Sloan Digital Sky Survey (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 σ8= 0.97 ± 0.06. We obtain consistent results if we use galaxy samples with a different magnitude threshold, or if we select galaxies by bJ-band rather than r-band luminosity and compare to data from the 2dF Galaxy Redshift Survey (2dFGRS). Our estimate for σ8 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.