Date Published:

June 1, 2014

Abstract:

We present a one per cent measurement of the cosmic distance scale fromthe detections of the baryon acoustic oscillations (BAO) in theclustering of galaxies from the Baryon Oscillation Spectroscopic Survey,which is part of the Sloan Digital Sky Survey III. Our results come fromthe Data Release 11 (DR11) sample, containing nearly one milliongalaxies and covering approximately 8500 square degrees and the redshiftrange 0.2 < z < 0.7. We also compare these results with those fromthe publicly released DR9 and DR10 samples. Assuming a concordanceΛ cold dark matter (ΛCDM) cosmological model, the DR11sample covers a volume of 13 Gpc³ and is the largest regionof the Universe ever surveyed at this density. We measure thecorrelation function and power spectrum, including density-fieldreconstruction of the BAO feature. The acoustic features are detected ata significance of over 7σ in both the correlation function andpower spectrum. Fitting for the position of the acoustic featuresmeasures the distance relative to the sound horizon at the drag epoch,r_d, which has a value of r_d,fid = 149.28 Mpc inour fiducial cosmology. We find D_V = (1264 ± 25Mpc)(r_d/r_d,fid) at z = 0.32 and D_V =(2056 ± 20 Mpc)(r_d/r_d,fid) at z = 0.57. At1.0 per cent, this latter measure is the most precise distanceconstraint ever obtained from a galaxy survey. Separating the clusteringalong and transverse to the line of sight yields measurements at z =0.57 of D_A = (1421 ± 20Mpc)(r_d/r_d,fid) and H = (96.8 ± 3.4 kms^-1 Mpc^-1)(r_d,fid/r_d). Ourmeasurements of the distance scale are in good agreement with previousBAO measurements and with the predictions from cosmic microwavebackground data for a spatially flat CDM model with a cosmologicalconstant.

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