期刊
ASTROPHYSICAL JOURNAL
卷 745, 期 1, 页码 -出版社
IOP Publishing Ltd
DOI: 10.1088/0004-637X/745/1/16
关键词
cosmological parameters; galaxies: clusters: general; galaxies: halos; large-scale structure of universe
资金
- DOE [DE-AC02-98CH10886, DE-AC03-76SF00515]
- NASA [PF9-00068]
- NSF [AST-1009505, AST-0907947]
- Division Of Astronomical Sciences
- Direct For Mathematical & Physical Scien [907947] Funding Source: National Science Foundation
- Division Of Astronomical Sciences
- Direct For Mathematical & Physical Scien [1009505] Funding Source: National Science Foundation
We place constraints on the average density (Omega(m)) and clustering amplitude (sigma(8)) of matter using a combination of two measurements from the Sloan Digital Sky Survey: the galaxy two-point correlation function, w(p)(r(p)), and the mass-to-galaxy-number ratio within galaxy clusters, M/N, analogous to cluster M/L ratios. Our w(p) (r(p)) measurements are obtained from DR7 while the sample of clusters is the maxBCG sample, with cluster masses derived from weak gravitational lensing. We construct nonlinear galaxy bias models using the Halo Occupation Distribution (HOD) to fit both w(p) (r(p)) and M/N for different cosmological parameters. HOD models that match the same two-point clustering predict different numbers of galaxies in massive halos when Omega(m) or sigma(8) is varied, thereby breaking the degeneracy between cosmology and bias. We demonstrate that this technique yields constraints that are consistent and competitive with current results from cluster abundance studies, without the use of abundance information. Using w(p) (r(p)) and M/N alone, we find Omega(0.5)(m) sigma(8) = 0.465 +/- 0.026, with individual constraints of Omega(m) = 0.29 +/- 0.03 and sigma(8) = 0.85 +/- 0.06. Combined with current cosmic microwave background data, these constraints are Omega(m) = 0.290 +/- 0.016 and sigma(8) = 0.826 +/- 0.020. All errors are 1 sigma. The systematic uncertainties that the M/N technique are most sensitive to are the amplitude of the bias function of dark matter halos and the possibility of redshift evolution between the SDSS Main sample and the maxBCG cluster sample. Our derived constraints are insensitive to the current level of uncertainties in the halo mass function and in the mass-richness relation of clusters and its scatter, making the M/N technique complementary to cluster abundances as a method for constraining cosmology with future galaxy surveys.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据