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斯隆数字巡天DR7亮红星系团的宇宙学约束

Cosmological Constraints from the Clustering of the Sloan Digital Sky Survey DR7 Luminous Red Galaxies

Beth A. Reid, Will J. Percival, Daniel J. Eisenstein, Licia Verde, David N. Spergel, Ramin A. Skibba, Neta A. Bahcall, Tamas Budavari, Masataka Fukugita, J. Ric… 展开作者

Beth A. Reid, Will J. Percival, Daniel J. Eisenstein, Licia Verde, David N. Spergel, Ramin A. Skibba, Neta A. Bahcall, Tamas Budavari, Masataka Fukugita, J. Richard Gott, James E. Gunn, Zeljko Ivezic, Gillian R. Knapp, Richard G. Kron, Robert H. Lupton, Timothy A. McKay, Avery Meiksin, Robert C. Nichol, Adrian C. Pope, David J. Schlegel, Donald P. Schneider, Michael A. Strauss, Chris Stoughton, Alexander S. Szalay, Max Tegmark, David H. Weinberg, Donald G. York, Idit Zehavi

摘要:

我们提出的重建晕密度场的功率谱来自一个样本的发光红星系(LRGs)从斯隆数字巡天第七次数据发布(DR 7)。晕的功率谱有一个直接的联系,以潜在的暗物质的功率为k <= 0.2小时/兆秒差距,以及进入准线性制度。这使我们能够在宇宙学分析中使用比kmax = 0.1 h/Mpc的分析多8倍的模式,正如SDSS团队对DR 4 LRG样本的分析所采用的那样(Tegmark et al. 2006)。0.02 < k < 0.2 h/Mpc时观测到的晕圈功率谱与我们的模型拟合良好:对于最佳拟合LCDM模型,对于40个自由度,chi ^2 = 39.6。对于谱指数n_s和Ω_bh^2 = 0.02265固定的幂律原始功率谱,我们发现Ω_mh^2 *(n_s/0.96)^0.13 = 0.141^{+0.009}-0.012},与CMB测量结果一致。晕功率谱还将重子拖曳时期的同动声视界与有效距离之比限制在z=0.35:rs/DV(0.35)= 0.1097^{+0.0039}-0.0042}。将Halo功率谱测量结果与WMAP 5年的观测结果相结合,得到了平坦LCDM模式的Ω_m = 0.289 +/- 0.019和H_0 = 69.4 +/-1.6km/s/Mpc。考虑到LCDM中的大质量中微子,我们发现\sum m_v < 0.62 eV,置信度为95%。如果我们把相对论性粒子的有效数Neff看作一个自由参数,我们发现Neff = 4.8^{+1.8}_{-1.7}。结合Kowalski等人(2008)的超新星样本,我们得到了具有常数暗能量状态方程w的开放宇宙学的Ω_{tot} = 1.011 +/- 0.009和w = -0.99 +/- 0.11。

英文摘要:

We present the power spectrum of the reconstructed halo density field derived from a sample of Luminous Red Galaxies (LRGs) from the Sloan Digital Sky Survey Seventh Data Release (DR7). The halo power spectrum has a direct connection to the underlying dark matter power for k <= 0.2 h/Mpc, well into the quasi-linear regime. This enables us to use a factor of ~8 more modes in the cosmological analysis than an analysis with kmax = 0.1 h/Mpc, as was adopted in the SDSS team analysis of the DR4 LRG sample (Tegmark et al. 2006). The observed halo power spectrum for 0.02 < k < 0.2 h/Mpc is well-fit by our model: chi^2 = 39.6 for 40 degrees of freedom for the best fit LCDM model. We find Ω_m h^2 * (n_s/0.96)^0.13 = 0.141^{+0.009}_{-0.012} for a power law primordial power spectrum with spectral index n_s and Ω_b h^2 = 0.02265 fixed, consistent with CMB measurements. The halo power spectrum also constrains the ratio of the comoving sound horizon at the baryon-drag epoch to an effective distance to z=0.35: r_s/D_V(0.35) = 0.1097^{+0.0039}_{-0.0042}. Combining the halo power spectrum measurement with the WMAP 5 year results, for the flat LCDM model we find Ω_m = 0.289 +/- 0.019 and H_0 = 69.4 +/- 1.6 km/s/Mpc. Allowing for massive neutrinos in LCDM, we find \sum m_ν < 0.62 eV at the 95% confidence level. If we instead consider the effective number of relativistic species Neff as a free parameter, we find Neff = 4.8^{+1.8}_{-1.7}. Combining also with the Kowalski et al. (2008) supernova sample, we find Ω_{tot} = 1.011 +/- 0.009 and w = -0.99 +/- 0.11 for an open cosmology with constant dark energy equation of state w.

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