Baryon Acoustic Oscillations in the Sloan Digital Sky Survey Data Release 7 Galaxy Sample - Astrophysics > Cosmology and Nongalactic AstrophysicsReport as inadecuate




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Abstract: The spectroscopic Sloan Digital Sky Survey SDSS Data Release 7 DR7 galaxysample represents the final set of galaxies observed using the original SDSStarget selection criteria. We analyse the clustering of galaxies within thissample, including both the Luminous Red Galaxy LRG and Main samples, and alsoinclude the 2-degree Field Galaxy Redshift Survey 2dFGRS data. BaryonAcoustic Oscillations are observed in power spectra measured for differentslices in redshift; this allows us to constrain the distance-redshift relationat multiple epochs. We achieve a distance measure at redshift z=0.275, ofr sz d-D V0.275=0.1390+-0.0037 2.7% accuracy, where r sz d is thecomoving sound horizon at the baryon drag epoch,D Vz=1+z^2D A^2cz-Hz^1-3, D Az is the angular diameter distance andHz is the Hubble parameter. We find an almost independent constraint on theratio of distances D V0.35-D V0.2=1.736+-0.065, which is consistent at the1.1sigma level with the best fit Lambda-CDM model obtained when combining ourz=0.275 distance constraint with the WMAP 5-year data. The offset is similar tothat found in previous analyses of the SDSS DR5 sample, but the discrepancy isnow of lower significance, a change caused by a revised error analysis and achange in the methodology adopted, as well as the addition of more data. UsingWMAP5 constraints on Omega bh^2 and Omega ch^2, and combining our BAO distancemeasurements with those from the Union Supernova sample, places a tightconstraint on Omega m=0.286+-0.018 and H 0 = 68.2+-2.2km-s-Mpc that is robustto allowing curvature and non-Lambda dark energy. This result is independent ofthe behaviour of dark energy at redshifts greater than those probed by the BAOand supernova measurements. abridged



Author: Will J. Percival, Beth A. Reid, Daniel J. Eisenstein, Neta A. Bahcall, Tamas Budavari, Joshua A. Frieman, Masataka Fukugita, Jame

Source: https://arxiv.org/







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