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arXiv 0907.1660astro-ph.CO
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Sloan数字巡天数据第7版星系样本中的重子声学振荡

Baryon Acoustic Oscillations in the Sloan Digital Sky Survey Data Release 7 Galaxy Sample

Will J. Percival, Beth A. Reid, Daniel J. Eisenstein, Neta A. Bahcall, Tamas Budavari, Joshua A. Frieman, Masataka Fukugita, James E. Gunn, Zeljko Ivezic, Gilli… 展开作者

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

摘要:

光谱斯隆数字巡天(SDSS)数据发布7(DR 7)星系样本代表了使用原始SDSS目标选择标准观察到的最终星系集。我们分析了这个样本中的星系团,包括亮红星系(LRG)和主样本,还包括2度场星系红移巡天(2dFGRS)数据。在红移不同切片的功率谱中观察到了重子声学振荡,这使我们能够在多个历元上约束距离-红移关系。在红移z=0.275处,我们得到了r_s(z_d)/D_V(0.275)=0.1390+/-0.0037(2.7%精度),其中r_s(z_d)是重子拖曳时的同动声视界,D_V(z)=[(1+z)^2D_A^2cz/H(z)]^(1/3),D_A(z)是角直径距离,H(z)是哈勃参数。我们发现一个几乎独立的距离比D_V(0.35)/D_V(0.2)=1.736+/-0.065的约束条件,这与将我们的z=0.275距离约束条件与WMAP 5年数据相结合得到的最佳拟合Lambda CDM模型在1.1 σ水平上是一致的。该偏移量与先前对SDSS DR 5样本进行的分析中发现的偏移量相似,但现在差异的显著性较低,这是由于修订了误差分析和所采用方法的变化以及增加了更多数据而引起的变化。使用WMAP 5对Omega_bh^2和Omega_ch^2的约束,并结合我们的BAO距离测量结果和来自联合超新星样本的测量结果,对Omega_m=0.286+/-0.018和H_0 = 68.2+/-2.2km/s/Mpc进行了严格的约束,这对于曲率和非λ暗能量是鲁棒的。这一结果与红移大于BAO和超新星测量所探测的红移的暗能量的行为无关。(节略)

英文摘要:

The spectroscopic Sloan Digital Sky Survey (SDSS) Data Release 7 (DR7) galaxy sample represents the final set of galaxies observed using the original SDSS target selection criteria. We analyse the clustering of galaxies within this sample, including both the Luminous Red Galaxy (LRG) and Main samples, and also include the 2-degree Field Galaxy Redshift Survey (2dFGRS) data. Baryon Acoustic Oscillations are observed in power spectra measured for different slices in redshift; this allows us to constrain the distance--redshift relation at multiple epochs. We achieve a distance measure at redshift z=0.275, of r_s(z_d)/D_V(0.275)=0.1390+/-0.0037 (2.7% accuracy), where r_s(z_d) is the comoving sound horizon at the baryon drag epoch, D_V(z)=[(1+z)^2D_A^2cz/H(z)]^(1/3), D_A(z) is the angular diameter distance and H(z) is the Hubble parameter. We find an almost independent constraint on the ratio of distances D_V(0.35)/D_V(0.2)=1.736+/-0.065, which is consistent at the 1.1sigma level with the best fit Lambda-CDM model obtained when combining our z=0.275 distance constraint with the WMAP 5-year data. The offset is similar to that found in previous analyses of the SDSS DR5 sample, but the discrepancy is now of lower significance, a change caused by a revised error analysis and a change in the methodology adopted, as well as the addition of more data. Using WMAP5 constraints on Omega_bh^2 and Omega_ch^2, and combining our BAO distance measurements with those from the Union Supernova sample, places a tight constraint on Omega_m=0.286+/-0.018 and H_0 = 68.2+/-2.2km/s/Mpc that is robust to allowing curvature and non-Lambda dark energy. This result is independent of the behaviour of dark energy at redshifts greater than those probed by the BAO and supernova measurements. (abridged)

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