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亮红星系的成团I：大尺度红移空间畸变

Clustering of luminous red galaxies I: large scale redshift space distortions

Anna Cabre, Enrique Gaztanaga

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31 pages, 65 figures
发表信息：
Mon.Not.Roy.Astron.Soc.393:1183-1208,2009
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摘要：

这是一个系列的第一篇论文，我们研究的LRG星系在最新的光谱SDSS数据发布，DR6，其中有75000 LRG星系覆盖超过1 $Gpc^3/h^3$在$0.15<z<0.47$。在这里，我们重点关注$\xips$中的红移空间失真建模，即大尺度上不同视线和垂直方向上的2点相关性。%和远离视线。我们使用大型模拟仿真来研究模型和误差的有效性。我们发现，在数据中的错误占主导地位的散粒噪声项，这是40%以上的泊松误差常用。我们首先使用归一化的四极杆为整个样本（平均z=0.34），以估计$β=f(Ω_m)/b=0.34 \pm 0.03$，其中$f(Ω_m)$是线性速度增长因子和$b$是线性偏置参数，涉及星系的大尺度上的物质波动。接下来，我们使用完整的$\xips$平面来找到$Ω_{0m}= 0.245 \pm 0.020$（h=0.72）和偏置幅度$b σ_8 = 1.56 \pm 0.09$。对于标准重力，我们可以结合这些测量来打破简并，并找到$σ_8=0.85 \pm 0.06$，$b=1.85 \pm 0.25$和$f(Ω_m)=0.64 \pm 0.09$。我们提出了修正的重力理论的约束条件，并发现只要$0.80<σ_8<0.92$，标准重力与数据是一致的。我们还计算了与WMAP 5的互相关，并展示了这两种测量增长历史的方法是如何互补的，以约束非标准的重力模型。最后，我们展示了不同红移切片的结果，包括一个突出的BAO峰在不同的红移。（节录）

英文摘要：

This is the first paper of a series where we study the clustering of LRG galaxies in the latest spectroscopic SDSS data release, DR6, which has 75000 LRG galaxies covering over 1 $Gpc^3/h^3$ at $0.15<z<0.47$. Here we focus on modeling redshift space distortions in $\xips$, the 2-point correlation in separate line-of-sight and perpendicular directions, on large scales. % and away from the line-of-sight. We use large mock simulations to study the validity of models and errors. We show that errors in the data are dominated by a shot-noise term that is 40% larger than the Poisson error commonly used. We first use the normalized quadrupole for the whole sample (mean z=0.34) to estimate $β=f(Ω_m)/b=0.34 \pm 0.03$, where $f(Ω_m)$ is the linear velocity growth factor and $b$ is the linear bias parameter that relates galaxy to matter fluctuations on large scales. We next use the full $\xips$ plane to find $Ω_{0m}= 0.245 \pm 0.020$ (h=0.72) and the biased amplitude $b σ_8 = 1.56 \pm 0.09$. For standard gravity, we can combine these measurements to break degeneracies and find $σ_8=0.85 \pm 0.06$, $b=1.85 \pm 0.25$ and $f(Ω_m)=0.64 \pm 0.09$. We present constraints for modified theories of gravity and find that standard gravity is consistent with data as long as $0.80<σ_8<0.92$. We also calculate the cross-correlation with WMAP5 and show how both methods to measure the growth history are complementary to constrain non-standard models of gravity. Finally, we show results for different redshift slices, including a prominent BAO peak in the monopole at different redshifts. (Abridged)

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