The Three-Dimensional Power Spectrum of Galaxies from the Sloan Digital Sky Survey
The Three-Dimensional Power Spectrum of Galaxies from the Sloan Digital Sky Survey
复制标题
DOI：
10.1086/382125
复制
发表时间：
2003-10
期刊：
影响因子：
--
通讯作者：
M. Tegmark;M. Blanton;M. Strauss;F. Hoyle;D. Schlegel;R. Scoccimarro;M. Vogeley;D. Weinberg
中科院分区：
文献类型：
--
作者：
M. Tegmark;M. Blanton;M. Strauss;F. Hoyle;D. Schlegel;R. Scoccimarro;M. Vogeley;D. Weinberg
我们利用斯隆数字巡天的205,443个星系样本测量了大尺度实空间功率谱P(K)，覆盖了2417个有效平方度，平均红移z≈为0.1。我们使用了一种基于矩阵的方法，使用伪Karhunen-Loève本征模，在22个k带中产生了不相关的最小方差测量，这些测量既有集群力又有由于红移空间扭曲而导致的各向异性，具有窄的和良好的窗函数，范围在0.02h MPC-1<；k<；0.3h MPC-1。我们特别注意建模、量化和校正潜在的系统误差、非线性红移失真和由光度相关的偏差引起的人为红移。我们的结果对于忽略角密度和径向密度波动是稳健的，并且在天空的不同部分是一致的。我们的最终结果是对真实空间物质功率谱P(K)的测量，直到未知的总体乘法偏差因子。我们的计算表明，对于k<；0.1h MPC-1，这个偏差因子与尺度无关，好于几个百分点，从而使我们的结果与威尔金森微波各向异性探测器卫星等其他实验的数据相结合，对精确测量宇宙学参数很有用。功率谱不能很好地用单一的幂定律来描述，但明确地显示出曲率。对于L*星系，当重子分数Ωb/σm=0.17和哈勃参数h=0.72时，我们的测量结果与一个扁平的标度不变绝热宇宙学模型很好地符合，hΩm=0.213±0.023，Ω8=0.89±0.02，宇宙学解释在配文中给出。
We measure the large-scale real-space power spectrum P(k) by using a sample of 205,443 galaxies from the Sloan Digital Sky Survey, covering 2417 effective square degrees with mean redshift z ≈ 0.1. We employ a matrix-based method using pseudo-Karhunen-Loève eigenmodes, producing uncorrelated minimum-variance measurements in 22 k-bands of both the clustering power and its anisotropy due to redshift-space distortions, with narrow and well-behaved window functions in the range 0.02 h Mpc-1 < k < 0.3 h Mpc-1. We pay particular attention to modeling, quantifying, and correcting for potential systematic errors, nonlinear redshift distortions, and the artificial red-tilt caused by luminosity-dependent bias. Our results are robust to omitting angular and radial density fluctuations and are consistent between different parts of the sky. Our final result is a measurement of the real-space matter power spectrum P(k) up to an unknown overall multiplicative bias factor. Our calculations suggest that this bias factor is independent of scale to better than a few percent for k < 0.1 h Mpc-1, thereby making our results useful for precision measurements of cosmological parameters in conjunction with data from other experiments such as the Wilkinson Microwave Anisotropy Probe satellite. The power spectrum is not well-characterized by a single power law but unambiguously shows curvature. As a simple characterization of the data, our measurements are well fitted by a flat scale-invariant adiabatic cosmological model with h Ωm = 0.213 ± 0.023 and σ8 = 0.89 ± 0.02 for L* galaxies, when fixing the baryon fraction Ωb/Ωm = 0.17 and the Hubble parameter h = 0.72; cosmological interpretation is given in a companion paper.